Aspiration monitoring system and method

ABSTRACT

A system for removal of blood or thrombus includes an aspiration catheter having an elongate shaft including an aspiration lumen having proximal end configured to couple to a vacuum source, and a distal end having an orifice, an elongate member configured for placement through the aspiration lumen and having a distal portion including a disruption element configured to disrupt thrombus within the aspiration lumen, and a monitoring device configured for removable connection in between the aspiration catheter and the vacuum source, and including a housing, a pressure sensor in fluid communication with an interior of the housing, a measurement device coupled to the pressure sensor and configured for measuring deviations in fluid pressure, and a communication device coupled to the measurement device and configured to generate an alert signal when a deviation in fluid pressure measured by the measurement device exceeds a pre-set threshold.

INCORPORATION BY REFERENCE TO ANY PRIORITY APPLICATIONS

This application claims the benefit of priority to U.S. ProvisionalApplication No. 62/387,537, filed on Dec. 23, 2015, and U.S. ProvisionalApplication No. 62/326,390, filed on Apr. 22, 2016, both of which areherein incorporated by reference in their entirety for all purposes.Priority is claimed pursuant to 35 U.S.C. § 119.

BACKGROUND OF THE INVENTION

Field of the Invention

The field of the invention generally relates to an aspiration system forremoving, by aspiration, undesired matter such as a thrombus from afluid carrying cavity, duct, or lumen of the body, such as a bloodvessel.

Description of the Related Art

A treatment method for removing undesired matter such as thrombus from ablood vessel of a patient involves use of an aspiration catheter havingelongate shaft formed with an aspiration lumen extending therein. Anaspiration catheter may also include a guidewire lumen for placement ofa guidewire, which is used to guide the aspiration catheter to a targetsite in the body. By applying a vacuum (i.e. negative pressure) to aproximal end of the aspiration lumen, for example, with a syringe havinga hub that is connected to the proximal end of the aspiration catheter,the matter can be aspirated into an aspiration port at the distal end ofthe aspiration catheter, into the aspiration lumen, and thus be removedfrom the patient.

SUMMARY OF THE INVENTION

In one embodiment, a system for removal of blood or thrombus includes avacuum source, an aspiration catheter having an elongate shaft includingan aspiration lumen having a proximal end and a distal end, the proximalend configured to couple to the vacuum source, the distal end having anorifice, an elongate member configured for placement through theaspiration lumen, the elongate member having a proximal portionconfigured to extend from the proximal end of the aspiration lumen, arotating device configured to couple to the proximal portion of theelongate member, the rotating device including a body and a rotationelement, the body configured to be gripped by a user and the rotationalelement configured to rotate the elongate member when the rotatingdevice is coupled to the elongate member, and a self-containedmonitoring device for real time monitoring of catheter aspiration,configured for removable connection in between the aspiration catheterand the vacuum source, including a housing having a first port adaptedfor detachable connection to the vacuum source and a second port adaptedfor detachable connection with the aspiration catheter, a pressuresensor in fluid communication with an interior of the housing, ameasurement device coupled to the pressure sensor and configured formeasuring deviations in fluid pressure, and a communication devicecoupled to the measurement device and configured to generate an alertsignal when a deviation in fluid pressure measured by the measurementdevice exceeds a pre-set threshold.

In another embodiment, a method for removing thromboembolic materialfrom a blood vessel in a patient includes providing a catheter having alumen, the lumen including a distal opening with a fixed inner diameter,providing an elongate member configured to be extendable through thelumen of the catheter and having a separator element disposed thereon,inserting the catheter into a blood vessel and positioning the catheteradjacent a body of thromboembolic material, applying negative pressureto the lumen for a first period of time to draw at least a portion ofthe body of thromboembolic material into the lumen, during at least aportion of the first period of time, reciprocating the separator elementa plurality of times between a first position at least partially withinthe distal opening and a second position distal to the distal opening,monitoring the negative pressure with a pressure transducer, andmeasuring one or more deviations in the negative pressure with ameasurement device coupled to the pressure transducer.

In yet another embodiment, system for removing thromboembolic materialfrom a blood vessel in a patient includes a catheter having a lumen, thelumen including a proximal end configured to couple to a vacuum sourceand a distal opening having a fixed inner diameter, an elongate memberextendable through the lumen of the catheter and having a separatorelement disposed thereon, the elongate member configured to allow thereciprocation of the separator element between a first position at leastpartially within the distal opening of the lumen and a second positiondistal to the distal opening of the lumen, and a monitoring device forreal time monitoring of catheter aspiration, including a housing havingan interior configured to be fluidly coupled to the lumen of thecatheter, a pressure sensor in fluid communication with the interior ofthe housing, a measurement device coupled to the pressure sensor andconfigured for measuring deviations in fluid pressure, and acommunication device coupled to the measurement device and configured togenerate an alert signal when one or more deviations in fluid pressuremeasured by the measurement device exceeds a pre-set threshold.

In still another embodiment, system for removal of blood or thrombusincludes a vacuum source, an aspiration catheter having an elongateshaft including an aspiration lumen having a proximal end and a distalend, the proximal end configured to couple to the vacuum source, thedistal end having an orifice, an elongate member configured forplacement through the aspiration lumen, the elongate member having aproximal portion configured to extend from the proximal end of theaspiration lumen and a distal portion including a disruption elementconfigured to disrupt thrombus within the aspiration lumen of theaspiration catheter, and a self-contained monitoring device for realtime monitoring of catheter aspiration, configured for removableconnection in between the aspiration catheter and the vacuum source,including a housing having a first port adapted for detachableconnection to the vacuum source and a second port adapted for detachablecoupling with the aspiration lumen, a pressure sensor in fluidcommunication with an interior of the housing, a measurement devicecoupled to the pressure sensor and configured for measuring deviationsin fluid pressure, and a communication device coupled to the measurementdevice and configured to generate an alert signal when a deviation influid pressure measured by the measurement device exceeds a pre-setthreshold.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a system for aspiration according to anembodiment of the present disclosure.

FIG. 2A is a view of an aspiration monitoring system according to afirst embodiment of the present disclosure.

FIG. 2B is a view of an aspiration monitoring system according to asecond embodiment of the present disclosure.

FIG. 3 is a view of an aspiration monitoring system according to a thirdembodiment of the present disclosure.

FIG. 4A is a sectional view of an aspiration catheter in a blood vesselprior to contact with a thrombus.

FIG. 4B is a sectional view of an aspiration catheter in a blood vesselupon contact with a thrombus.

FIG. 4C is a sectional view of an aspiration catheter during a loss ofvacuum.

FIG. 4D is a sectional view of thrombi being aspirated through anaspiration catheter.

FIG. 5A is a graphic representation of pressure vs. time for thecondition of FIG. 4A.

FIG. 5B is a graphic representation of pressure vs. time for thecondition of FIG. 4B.

FIG. 5C is a graphic representation of pressure vs. time for thecondition of FIG. 4C.

FIG. 5D is a graphic representation of pressure vs. time for thecondition of FIG. 4D.

FIG. 6 is a graphic representation of pressure and an output soundamplitude vs. time for an embodiment of an aspiration monitoring system.

FIG. 7 is a graphic representation of pressure and an output soundamplitude vs. time for an embodiment of an aspiration monitoring system.

FIG. 8 is a graphic representation of pressure and an output soundfrequency vs. time for an embodiment of an aspiration monitoring system.

FIG. 9 is a graphic representation of pressure and an output of soundfrequency vs. time for an embodiment of an aspiration monitoring system.

FIG. 10 is a plan view of a system for aspiration according to anotherembodiment of the present disclosure.

FIG. 11 is a plan view of a system for aspiration according to anotherembodiment of the present disclosure.

FIG. 12 is a detailed view of an aspiration monitoring system of thesystem for aspiration of FIG. 11.

FIG. 13 is a plan view of a system for aspiration according to anotherembodiment of the present disclosure.

FIG. 14 is a detailed view of an aspiration monitoring system of thesystem for aspiration of FIG. 13.

FIG. 15 is a diagrammatic view of a system for aspirating thrombusaccording to an embodiment of the present disclosure.

FIG. 16 is a diagrammatic view showing more detail of the proximalportion of the system for aspirating thrombus of FIG. 15.

FIG. 17 is a diagrammatic view of the distal end portion of the systemfor aspirating thrombus of FIG. 15.

FIG. 18 is a perspective view of a portion of a multi-purpose systemaccording to an embodiment of the present disclosure.

FIG. 19 is a detailed view of a proximal portion of the multi-purposesystem of FIG. 18.

FIG. 20 is a perspective view of a portion of a multi-purpose systemaccording to an embodiment of the present disclosure.

FIG. 21 is a detail view of the distal end of a multi-purpose catheterof the multi-purpose system of FIG. 20.

FIG. 22 is a detail view of a proximal portion of the multi-purposesystem of FIG. 20.

FIG. 23 is a detail view of a proximal portion of the multi-purposesystem of FIG. 20.

FIG. 24 is a detail view of a portion of the multi-purpose system ofFIG. 20.

FIG. 25 is a plan view of an aspiration catheter according to anembodiment of the present disclosure.

FIG. 26 is a plan view of a tubing set according to an embodiment of thepresent disclosure.

FIG. 27 is a plan view of a stopcock according to an embodiment of thepresent disclosure.

FIG. 28 is a plan view of a stopcock according to an embodiment of thepresent disclosure.

FIG. 29 is a plan view of a vacuum source according to an embodiment ofthe present disclosure.

FIG. 30 is a plan view of an aspiration system according to anembodiment of the present disclosure.

FIG. 31 is a plan view of an aspiration system according to anembodiment of the present disclosure.

FIG. 32 is a plan view of an aspiration system according to anembodiment of the present disclosure.

FIG. 33 is a plan view of an aspiration system according to anembodiment of the present disclosure.

FIG. 34 is a sectional view of a saline injection aspiration(thrombectomy) catheter according to an embodiment of the presentdisclosure, with a guidewire in place through the lumens.

FIG. 35 is a perspective view of the proximal end of a guiding catheterwith an aspiration catheter placed therein.

FIG. 36A is a perspective view of an aspiration catheter having aseparator according to an embodiment of the present disclosure.

FIG. 36B is a perspective view the aspiration catheter and separatorelement of FIG. 36A with the separator in a different position.

FIG. 37A is a perspective view of an aspiration system according to anembodiment of the present disclosure.

FIG. 37B is a perspective view the aspiration catheter and separatorelement of FIG. 37A with the separator in a different position.

FIG. 38 is a perspective view of an aspiration system according to anembodiment of the present disclosure.

FIG. 39 is a perspective view of the aspiration system of FIG. 38further incorporating a wire spinning device.

FIGS. 40A-40D are configurations of guidewires for spinning within anaspiration lumen of an aspiration system according to an embodiment ofthe present disclosure.

FIG. 41 is a partial sectional view of one embodiment of athromboembolic removal system, including a guide catheter, an aspirationcatheter, an aspiration pump, and a thromboembolic separator.

FIG. 42A is a perspective view of a distal portion of the separator ofFIG. 41.

FIG. 42B is a plan view of the separator of FIG. 42A.

FIG. 42C is a cross-section view taken along line 42C-42C in FIG. 42A.

FIG. 43 is a cross-section view similar to FIG. 42C, showing analternative separator embodiment.

FIGS. 44-47 are sequences of drawings schematically illustrating use ofthe system of FIG. 41 within the cerebral vasculature.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

The present invention relates to a monitoring, warning and communicationsystem for aspiration catheter systems. Clogging of aspirationcatheters, for example by large pieces of thrombus, is a common concernfor users. Techniques to avoid clogging/choking of material within thecatheter often involve rapidly, aggressively advancing the aspirationcatheter or gently plucking at edges of a thrombus to insure only smallpieces or portions are introduced at a time, pieces which are smallenough to not clog or occlude the aspiration lumen. When a devicebecomes clogged during use, the potential for inadvertent dislodgment ofthrombus downstream increases; this is referred to as distal embolism.As aspiration procedures of this type are often used in highly technicalemergent settings, early clog detection of the aspiration catheter forthe user during aspiration can contribute to the success of theprocedure and clinical outcome. Some sources have reported that up to50% of aspiration catheters used get clogged during use.

The user may have difficulty determining whether there is a vacuum inthe system of not. For example, the user may have difficulty determiningwhether the vacuum has been applied or not (e.g., the vacuum source hasbeen turned on or off). Additionally, the user may have difficultydetermining whether there has been a loss of vacuum in the system, forexample because of the syringe (or other vacuum source) being full offluid or because of a leak in the system. Blood is relatively opaque andcan coat the wall of the syringe, thus making it difficult to determinewhen the syringe becomes full. This makes it difficult to determinewhether sufficient vacuum is being applied to the aspiration catheter.The vacuum level may change to an unacceptable level even before thesyringe becomes full. Extension tubing or other tubing may also cause aloss in vacuum in the system. Certain tubing kinks may occur and may bedifficult for a user to see or identify. It is also difficult todetermine whether there is an air leak in the system, which can beanother cause for a loss of vacuum even before the syringe becomes fullof the aspirated fluid.

During the aspiration of thrombus with an aspiration catheter, it isdifficult to identify when thrombus is actively being aspirated, andwhen only blood is being aspirated. Typically it is desired to notaspirate sizable quantities of normal blood from blood vessels, becauseof the importance of maintaining normal blood volume and blood pressure.However, when tracking the tip of an aspiration catheter in proximity toa thrombus, it is difficult to know whether the aspiration catheter hasactively engaged a thrombus, whether it has aspirated at least a portionof the thrombus, or whether it is not engaged with the thrombus, and isonly aspirating blood. Though some aspiration catheters, such as thoseused in the peripheral blood vessels or in an arterio-venous fistula,may be around 50 cm or even less, the tip of an aspiration catheter mayin same cases be more than 90 cm from the hands of the user, or as muchas 135 cm from the hands of the user, or in some cases as much as 150cm, and the particular status of vacuum at the tip of the catheter isoften not known by the user. A user may thus be essentially plunging acatheter blindly without significant, usable sensory feedback. Thecatheter may have an outer diameter up to or even greater than 6 French,which can cause some concern of potential trauma inside a blood vessel.The use of aspiration catheters can therefore be inefficient, and causemore blood removal than desired, causing a user to minimize the lengthof the therapy and in severe cases necessitating blood transfusion. Anincreased volume of normal blood being aspirated also means that thevacuum source (e.g. syringe) will fill in a shorter amount of time, thusrequired more frequent replacement of the vacuum source. Distal embolismmay occur if the vacuum pressure is not sufficient, and yet the user isnot aware. In some cases, a syringe that is completely or mostly full orblood and/or thrombus may continue to be used, though in this state,there is not sufficient pressure to effectively aspirate thrombus orunwanted material, thus causing inefficient use of time, and lengtheningthe procedure. In some cases, the user may not realize the plunger ofthe syringe has mistakenly not been pulled back (to evacuate thesyringe). In some cases, the syringe itself may be defective, and aproper vacuum may not be achieved, without the user being aware. In somecases, kinked tubing, lines, or catheters may go unnoticed, because ofbad visibility in a procedural laboratory, or simply from the extent ofconcurrent activities being performed. In many cases, the user's eyesare oriented or focused on a monitor, for example a fluoroscopic monitoror other imaging monitor, or a monitor with patient vital data. Thoughthe user may be able to view flow through transparent or partiallytransparent lumens (such as extension tubing), in dim lighting withintermittent viewing, it is difficult for the user's mind to processflow of an opaque liquid (such as blood/thrombus). Even in good lightingwith a focused eye, the movement of fluid through extension tubing maynot present an accurate picture of the aspiration status, as the visualflow effect may be delayed in relation to the applied vacuum. More thanone medical device personnel may be sharing sensory information witheach other to attempt to build a current status in each other's minds ofthe aspiration procedure. When a user relies on another'sinterpretation, especially when either are multitasking, a false senseof the status may occur. A syringe attached to the aspiration cathetermay cause kinking, for example, if placed on an uneven surface. Thedistal opening in an aspiration lumen of an aspiration catheter may beprone to aspirating directly against the wall of a blood vessel, thusbeing temporarily stuck against the vessel wall, and stopping flowthroughout the aspiration lumen. In some cases, a vacuum that is toolarge may be accidentally or inappropriately applied to the aspirationlumen of the aspiration catheter, limiting effectiveness (for example,if it causes the walls surrounding the aspiration lumen to collapse andthus, cut off the significantly decrease the flow through the aspirationlumen). The syringes which are sometimes used as a vacuum source toconnect to an aspiration lumen of an aspiration catheter maymalfunction, and not be fully actuated/evacuated. But, even when thesyringe is functioning correctly, it will tend to fill up at difficultto predict moments, and thus commonly have periods of no applied vacuum.In the cases wherein a portion of clot/thrombus is being aspiratedthrough the aspiration lumen, a significant pressure drop may occur atthe current position of the thrombus, and thus, a sufficient vacuum mayonly exist from the proximal end of the aspiration lumen and distally upto the point of the thrombus. Thus, an insufficient vacuum may exist atthe distal end of the aspiration lumen, e.g., at the distal end of theaspiration catheter. The same situation may occur if there is an actualclog at some intermediate point within the aspiration lumen. In eitherof these conditions, because of the insufficient vacuum at the distalend of the aspiration lumen, there may be a risk of thrombus or embolibeing send distally in the vasculature, which may cause occlusion,stroke, pulmonary embolism, or other disorders, depending upon thelocation of the intervention. With current apparati and techniques,these situations are very difficult to detect when they occur. It hasbeen estimated that in as many as 50% of thrombus aspiration procedures,some sort of failure occurs.

An aspiration system 2 is illustrated in FIG. 1 and is configured toallow real time monitoring of catheter aspiration. The aspiration system2 comprises an aspiration catheter 4, a vacuum source 6, a valve 8,extension tubing 10, and an aspiration monitoring system 48 including anin-line pressure transducer 12. The aspiration catheter 4 has a proximalend 14 and a distal end 16 and an aspiration lumen 18 extending from theproximal end 14 to the distal end 16. The aspiration lumen 18 may besized for aspiration of thrombus, and in some embodiments may have aninner diameter of between about 0.38 millimeter (0.015 inches) and about2.54 millimeters (0.100 inches). The aspiration catheter 4 includes ahub 20 at its proximal end which may include a female luer connector 22.The aspiration lumen 18 at the distal end 16 of the aspiration catheter4 may include an angled orifice 24, which aids in the tracking throughtortuous or occluded vasculature. In some embodiments, a guidewire lumen26 is coupled to the distal end 16 of the aspiration catheter 4, and isconfigured to track over a guidewire 28. The vacuum source 6 maycomprise a syringe, and may be sized between 5 ml and 100 ml, or between20 ml and 60. The vacuum source 6 may comprise a VacLok® syringe, madeby Merit Medical, South Jordan, Utah. The vacuum source 6 may include abarrel 30 and plunger 32, with a lock 34 which is configured to retainthe plunger 32 in position in relation to the barrel 30, for example,when the plunger 32 is pulled back in direction D to create a negativepressure (vacuum) inside the barrel 30. In some embodiments, the vacuumsource 6 may comprise any other type of evacuatable reservoir, or maycomprise a vacuum pump. The vacuum source 6 is connected to theaspiration lumen 18 of the aspiration catheter 4 via the extensiontubing 10 and the valve 8. In some embodiments, the vacuum source 6 maybe connected directly to the aspiration lumen 18 of the aspirationcatheter 4. Male luer connectors 36 and female luer connectors 38 areindicated in FIG. 1. The valve 8 may be a standard two-way stopcock, asillustrated.

The pressure transducer 12 of the aspiration monitoring system 48 isconfigured to be fluidly coupled between the vacuum source 6 and theaspiration catheter 4. In FIG. 2A, the aspiration monitoring system 48is illustrated as a self-contained device of a first embodiment. Thepressure transducer 12 comprises a housing 40 having a cavity 42extending between a first port 44 and a second port 46. In someembodiments, the first port 44 comprises a female luer and the secondport 46 comprises a male luer. In some embodiments, the first port 44comprises a female luer lock and the second port 46 comprises a maleluer lock, each of which is attachable to and detachable from acorresponding luer lock of the opposite gender. The first port 44 isconfigured to be coupled to the vacuum source 6, either directly, orwith the valve 8 and/or extension tubing 10 connected in between. Thesecond port 46 is configured to be coupled to the aspiration lumen 18 ofthe aspiration catheter 4, for example, by coupling the second port 46directly or indirectly to the hub 20 of the aspiration catheter 4. Whenthe aspiration system 2 is used to aspirate body fluids and/ormaterials, for example blood and/or thrombus, the body fluids and/ormaterials are aspirated through the aspiration lumen 18 of theaspiration catheter from the angled orifice 24 at the distal end 16 tothe female luer connector 22 at the proximal end 14, then pass throughthe second port 46 of the pressure transducer 12 first, through thecavity 42, and then through the first port 44. Depending on the amountof amount of vacuum (negative pressure) applied by the vacuum source 6,and the amount of flow resistance and resulting pressure drop along theaspiration system 2, the pressure within the cavity 42 will vary. Forexample, a more viscous fluid like blood, or a fluid having solid,semi-solid, or gel-like particles or portions, will cause more flowresistance through the relatively small aspiration lumen 18 of theaspiration catheter 4 than would water or normal saline solution. Thusthe pressure within the cavity 42 of the pressure transducer 12 willdecrease (the amount of vacuum will increase) as the flow resistance inthe aspiration lumen 18 increases.

For definition purposes, when speaking of the amount of vacuum, apressure of, for example, −15,000 pascal (−2.18 pounds per square inch,or psi) is a “larger vacuum” than −10,000 pascal (−1.45 psi).Additionally, −15,000 pascal is a “lower pressure” than −10,000 pascal.Furthermore, −15,000 pascal has a larger “absolute vacuum pressure” thandoes −10,000 pascal, because the absolute value of −15,000 is largerthan the absolute value of −10,000. In FIG. 2A, a vacuum sensor 50 isdisposed within the cavity 42 of the housing 40 and is in fluidcommunication with fluid that passes through the cavity 42. The vacuumsensor 50 may be a standard pressure sensor or transducer, including apressure sensor designed primarily for measuring positive pressure. Itmay use any type of pressure sensing technology known in the art,including MEMS Technology. In some embodiments, the vacuum sensor 50 isconfigured for highest accuracy and/or precision within the range ofpressures between about 0 pascal to about −101,325 pascal (−14.70 psi),or between about −45,000 pascal (−6.53 psi) and about −90,000 pascal(−13.05 psi), or between about −83,737 pascal (−12 psi) and about−96,527 pascal (−14 psi). In some embodiments, the power requirement forthe vacuum sensor may range from 2.5 volts DC to 10 volts DC. In someembodiments, the vacuum sensor 50 may be an analog gauge with an outputvoltage. In the self-contained embodiment of the FIG. 2A, the vacuumsensor 50 is powered by one or more battery 52. Based on the powerrequirements of the vacuum sensor 50, and the power requirements ofother components of the aspiration monitoring system 48 describedherein, in some embodiments the one or more battery 52 may range between1.5 volts and nine volts. Also contained within the housing is ameasurement device 54, which in some embodiments may comprise amicroprocessor. The measurement device 54 is coupled to the vacuumsensor 50 and receives signals from the vacuum sensor 50 indicative ofreal time measured pressure. In some embodiments, the measurement device54 includes a memory module 56 in which information is stored that maybe used by the measurement device 54, for example, in calculations.Information may include, for example, an array of one or more pressurevalues. In some embodiments, the array of one or more pressure valuesmay be correlated with one or more different corresponding system modelsor catheter models. The vacuum sensor 50 may be used in some cases fordetecting the presence or amount of vacuum alone, for the purpose ofmonitoring whether the vacuum source 6 (e.g., syringe) is significantlyfull, and thus needs to be changed. The vacuum sensor 50 may be used insome cases for detecting whether there is a vacuum in the system of not.For example, whether the vacuum has been applied or not (e.g., thevacuum source has been turned on or off).

One or more communication devices 58 a, 58 b, 58 c are included withinthe aspiration monitoring system 48 and are coupled to the measurementdevice 54. Each of the one or more communication devices 58 a-c areconfigured to generate a type of alert comprising an alert signal 60a-c, in response at least in part to activity and output of themeasurement device 54. In some embodiments, the communication device 58a may include one or more LEDs (light emitting diodes) configured togenerate a visible alert via a visible alert signal 60 a, such as lightthat is continuously illuminated, or is illuminated in a blinkingpattern. In some embodiments, the LEDs may be oriented on multiple sidesof the communication device 58 a, so that they may be easily seen from avariety of different locations. In some embodiments, lights other thanLEDs may be used. Light pipes or other lighting conduits may also beincorporated in embodiments, to further place visual indicators atmultiple locations and/or orientations. In some embodiments, thecommunication device 58 b may include one or more vibration generatorsconfigured to generate a tactile alert via a tactile alert signal 60 b,which may include, but is not limited to, vibration or heat. In someembodiments, the vibration device may be similar to a video gamecontroller. In some embodiments, the vibration generator may comprise apiezoelectric device which is configured to vibrate when a voltage isapplied. In some embodiments, the communication device 58 c may includeone or more sound generating devices configured to generate an audiblealert via an audible alert signal 60 c, such as a continuous noise, or arepeating noise. The communication device 58 c in some embodiments maycomprise a loudspeaker for generation of any variety of sounds, at anyvariety of frequencies (Hz) or sound pressures (dB) within the humanaudible range and/or human tolerance range. In some embodiments, thesound generating device may comprise a buzzer which is configured tosound one or more audible pitches when a voltage is applied. In someembodiments a piezoelectric device, such as that described in relationto the communication device 58 b may also serve as a sound generatingdevice, included as communication device 58 c. The alert signal 60 a-ccan at times serve as a “wake up” alarm for the user, in cases where theuser has become too focused on other factors during the procedure.

A user of an aspiration system 2 may desire to be notified of severalconditions which may occur during use of the aspiration system 2. Thesepotential conditions include, but are not limited to clogging, a loss ofvacuum due to filling of the vacuum source 6 and or a breach, break orpuncture in the aspiration system 2, and the engagement or aspiration ofnon-fluid, solid or semi-solid material such as thrombus. The aspirationmonitoring system 48 of FIG. 2A is configured to alert users of anaspiration system 2 about real time status of the aspiration system 2,including operational conditions, which include: whether vacuum is beingapplied or not; flow conditions, which include whether a thrombus isengaged, whether a thrombus is being actively aspirated, whether thesystem is leaking air, whether the system is clogged, whether the vacuumsource 6 is full and/or needs to be changed; or other potential set upissues. The real time feedback provided frees a user or operator fromthe need of excessive personal monitoring of the vacuum source 6,extension tubing 10, or other portions of the aspiration system 2, forimproper or undesired flow or operation conditions, and thus allows theuser to focus more attention on the patient being treated. The user iskept aware of whether a clot is being aspirated or has been aspirated,or whether there is a clog. Additionally, the user is kept aware ofwhether there is too large an amount of blood being removed from thepatient, or whether there are fault conditions like system leak ortubing kink. A tubing kink distal to the vacuum sensor 50 may beidentified (for example by an increase in measured vacuum) and a tubingkink proximal to the vacuum sensor 50 may be identified (for example, bya loss or degradation of vacuum). In some cases, the user may attempt tooperate the catheter with a vacuum source 6 that is already full (andthus has no significant vacuum). In some cases, a user may even forgetto open the valve 8 to begin suction, but the aspiration monitoringsystem, 48 can also identify that the system is not yet functioning, andcommunicate a list of potential errors or specific errors (for theparticular pressure waveform measured). By having the real-timeawareness of the many factors related to the operating status, theprocedure is made safer, the time of the procedure may be reduced, andblood loss may be reduced.

The pressure transducer 12 of the aspiration monitoring system 48 isconfigured to continuously measure and monitor the absolute pressureamplitude within the closed system of the aspiration system 2, and alsois configured to measure and monitor the relative pressure over time todetect noteworthy flow changes within the flow circuit of the aspirationsystem 2. Some changes are discernible via absolute pressuremeasurement, while more subtle pressure deflections may be compared to astored library in memory. Noteworthy conditions may be signaled to theuser when appropriate. In some embodiments, the unfiltered signal may beamplified by an amplifier and filtered by a filter, for example, toincrease the signal-to-noise ratio. Examples of the (background) noise57 in an unfiltered signal can be seen in FIGS. 5A-5D (labeled in FIG.5A). In some embodiments, one or more algorithms may be used, asdescribed herein, to identify particular conditions of interest.

FIG. 2B illustrates a second embodiment of an aspiration monitoringsystem 62 having a pressure transducer 12 having a vacuum sensor 50disposed within the cavity 42 of a housing 40. The vacuum sensor 50 maybe powered by at least one battery 52. In some embodiments, the pressuretransducer 12 may be reusable, and may be configured to allow chargingof the battery 52, or of a capacitor (not shown) by direct chargingmethods, or by inductive power transfer methods and devices known in theart. Unlike the aspiration monitoring system 48 of FIG. 2A, theaspiration monitoring system 62 of FIG. 2B comprises a measurementdevice 64, memory module 66, and communication device 68 which areexternal to the pressure transducer 12. A power module 72, alsoexternal, may be used to power any of the measurement device 64, memorymodule 66, or communication device 68. The communication device 68 maybe any of the communication device 58 a, 58 b, 58 c described inrelation to the aspiration monitoring system 48 of FIG. 2A, and areconfigured to product an alert via an alert signal 70. The communicationdevice 68 may be portable so that it may be positioned close to theuser.

In some embodiments, the communication device 68 may be wearable by theuser. FIG. 3 illustrates an aspiration monitoring system 78 whichincludes an antenna 80 coupled to a measurement device 76. Themeasurement device 76 is similar to the measurement device 54 of priorembodiments, except that it wirelessly sends a communication signal 84via the antenna 80 to a corresponding antenna 82 of a communicationdevice 74. In some embodiments, the communication device 74 comprises awristband which the user wears, and which may include a vibrationgenerator or heat generator. In some embodiments, the communicationdevice 74 comprises an audio speaker which may be attached to equipmentor even to the patient or user. In some embodiments, the communicationdevice 74 comprises an audio speaker on an earpiece or earbud that theuser may wear. In some embodiments, Bluetooth® communication technologymay be used. The real time feedback supplied by the aspirationmonitoring system 62 may decrease the time that the aspiration system 2is actively aspirating without being engaged with a thrombus, thusminimizing the amount of nonthrombotic blood lost by aspiration. Thismay be particularly beneficial in larger bore catheters, for example incatheters having a diameter of 7 French or larger. The real timefeedback may also minimize the amount of total time that catheters aretracked back-and-forth through the blood vessels, minimizing potentialdamage to the intima of the blood vessels, dissection of the bloodvessels, or distal embolization. By lowering the risk of the aspirationcatheter tip getting caught (via suction) against the blood vessel wall,the distal end of the aspiration lumen may be more aggressively designedfor optimized aspiration characteristics. The technique of using theaspiration catheter may additionally be able to be performed in a moresophisticated manner, with continual or continuous knowledge of thevacuum status. For example, a piece of thrombus may be aspirated,followed by a “chaser” of blood aspiration, followed by another piece ofthrombus, etc.

FIG. 4A illustrates the distal end 16 of an aspiration catheter 4 withina blood vessel 86 having at least one thrombus 88. The aspirationcatheter 4 is being advanced in a forward direction F, but the distalend 16 of the aspiration catheter 4 has not yet reached the proximalextremity 94 of the thrombus 88. A vacuum source 6 (FIG. 1) has beencoupled to the aspiration lumen 18 of the aspiration catheter 4 andactivated (i.e. the valve 8 is open) causing blood 96 to be aspiratedinto the aspiration lumen 18 (arrows A). Turning to FIG. 5A, acorresponding curve 98 is represented for the normal fluid (e.g. blood)vacuum over time for the condition of FIG. 4A. The curve 98 representsvacuum pressure over time sensed by the vacuum sensor 50 of any of theembodiments presented. No leaks are present and no thrombus is beingevacuated, and therefore the curve 98 includes a downward slope 99 whenthe vacuum source 6 increases the vacuum up (lowers the pressure) withinthe cavity 42 of the pressure transducer 12 to a relatively steadystate. The steady pressure curve 97 continues while blood 96 is beingaspirated. As the vacuum is decoupled from the aspiration lumen 18, forexample by closing the valve 8 or by detaching any two of the ports(e.g. luers), or if the vacuum source 6 fills completely with blood 96,then an upward slope 95 is measured.

The measurement device 54, 64 is configured to compare the curve 97 withinformation stored in the memory module 56, 66 to identify thiscondition. In some embodiments, the measurement device 54, 64 uses analgorithm to make the comparison. In some embodiments, the measurementdevice 54, 64 then sends a signal to the communication device 58 a-c,74, and the communication device 58 a-c, 74 generates an appropriatealert. Communication device 58 a, for example a particular color LED,may be illuminated, or an LED may flash in a particular pattern ornumber of flashes. Communication device 58 b may create a characteristicsound, or may generate an audio message in a number of languages. Forexample, the audio message may state, “Thrombus encountered,” or “Nothrombus encountered.” A different type of sound may be used for each ofa plurality of “modes”: “Thrombus encountered,” “Actively flowing,” “NoVacuum” For example, a buzzing sound for “Thrombus encountered,” a beepfor “No vacuum,” etc. Communication device 58 c may vibrate or heat in acharacteristic pattern, for example, a certain number of repetitions ora certain frequency between repetitions. The user may determine that anadditional fluoroscopic image (e.g. angiography) or other imagingmodalities may be necessary to better identify the location of thethrombus 88.

FIG. 4B illustrates the distal end 16 of an aspiration catheter 4advanced to a position such that the distal end 16 of the aspirationcatheter 4 contacts the proximal extremity 94 of the thrombus 88. Thecorresponding curve 93 in FIG. 5B represents vacuum pressure over timesensed by the vacuum sensor 50 of any of the embodiments presented. Thecurve 93 initially has a downward slope 99 followed by a steady pressurecurve 97, as in the condition of FIG. 4A, graphed in FIG. 5A, however,when the distal end 16 of the aspiration catheter 4 contacts theproximal extremity 94 of the thrombus 88, if the aspiration causes aportion of the thrombus 88 (for example a large or relatively hardportion) to enter and become trapped in the aspiration lumen 18, then aclog condition occurs. A similar condition occurs if the distal end 16of the aspiration catheter 4 is caught on the thrombus 88 by the vacuum,with virtually nothing flowing through the aspiration lumen 18. Ineither condition, the curve 93 includes a deviation (or disturbance) influid pressure 91. If the clog (or stuck condition) continues, then aflat, depressed pressure 89 is measured.

The measurement device 54, 64 is configured to compare the curve 93 withinformation stored in the memory module 56, 66 to identify thiscondition. In some embodiments, the measurement device 54, 64 uses analgorithm to make the comparison. In some embodiments, a pre-setpressure differential ΔP₁ may be stored in the memory module 56, 66 as athreshold, whereby the measurement of a pressure difference 81 less thanthis threshold does not result in the measurement device 54, 64commanding the communication device 58 a-c, 74 to send an alert signal60 a-c, 70. In some embodiments, when the pressure difference 81 isgreater than (or greater than or equal to) the pre-set pressuredifferential ΔP₁, the measurement device 54, 64 then sends a signal tothe communication device 58 a-c, 74, and the communication device 58a-c, 74 generates an appropriate alert. Communication device 58 a, forexample a particular color LED, may be illuminated, or an LED may flashin a particular pattern or number of flashes. Communication device 58 bmay create a characteristic sound, or may generate an audio message in anumber of languages. For example, the audio message may state, “ClogCondition.” Communication device 58 c may vibrate or heat in acharacteristic pattern, for example, a certain number of repetitions ora certain frequency between repetitions. When the user realizes that theclog condition is present, the user may pull on the aspiration catheter4 and readvance it, in an attempt to contact a portion of the thrombus88 that can be aspirated. If a portion of the thrombus is clogged in theaspiration lumen 18, and repositioning of the aspiration catheter 4 doesnot produce good results, the aspiration catheter 4 can be removed andthe aspiration system 2 can be repurged, for example by a positivepressurization.

FIG. 4C illustrates the distal end 16 of the aspiration catheter 4 in ageneral situation during which a breach in the aspiration system 2 hasoccurred. For example, a break, leak, puncture, pinhole, loosening, ordisconnection may cause air to be pulled into the aspiration lumen 18 ofthe aspiration catheter 4, the cavity 42 of the pressure transducer 12,of the interior of the extension tubing 10, valve 8, or vacuum source 6.As graphed in the curve 85 of FIG. 5C, a downward slope 99 and asubsequent steady pressure curve 97 are measured, but at the point intime of the breach 87 an upward slope 83 begins.

The measurement device 54, 64 is configured to compare the curve 85 withinformation stored in the memory module 56, 66 to identify thiscondition. In some embodiments, the measurement device 54, 64 uses analgorithm to make the comparison. In some embodiments, the measurementdevice 54, 64 then sends a signal to the communication device 58 a-c,74, and the communication device 58 a-c, 74 generates an appropriatealert. Communication device 58 a, for example a particular color LED,may be illuminated, or an LED may flash in a particular pattern ornumber of flashes. Communication device 58 b may create a characteristicsound, or may generate an audio message in a number of languages. Forexample, the audio message may state, “System Leak.” Communicationdevice 58 c may vibrate or heat in a characteristic pattern, forexample, a certain number of repetitions or a certain frequency betweenrepetitions. Upon receiving the alert, the user will check thecomponents of the aspiration system 2 and either fix the breach orreplace one or more of the components of the aspiration system 2. Forexample, in some cases, the communication device 58 a-c, 74 may alertthe user when the measurement device 54, 64 confirms a loss of vacuum,allowing the user to change or recharge the vacuum source 6, which hasbecome depleted (e.g. by filling with blood and/or thrombus).

FIG. 4D illustrates the distal end 16 of the aspiration catheter 4during the successful aspiration of pieces or portions 90 of thethrombus 88. In some cases, the pieces or portions 90 may follow atortuous path 92, due to disturbances or collisions with the inner wallof the aspiration lumen 18 while being pulled through the aspirationlumen 18. In some cases, the pieces or portions 90 may catch and slipwithin the inner wall of the aspiration lumen 18, for example, do tovariance of the inner diameter of the aspiration lumen 18 along thelength. Either of these situations can cause a corresponding series ofincreases and decreases in the pressure being sensed by the pressuretransducer 12, while the pieces or portions 90 are traveling through theaspiration lumen 18. As graphed in the curve 79 of FIG. 5D, a downwardslope 99 and a subsequent steady pressure curve 97 are measured, but asthe pieces or portions 90 of thrombus 88 travel down the aspirationlumen 18 of the aspiration catheter 4, a deviation 77 of fluid pressurecomprising one or more decreases and increases in pressure (increasesand decreases in vacuum pressure) is measured. As the pieces or portions90 of thrombus 88 exit the proximal end of the aspiration lumen 18 ofthe aspiration catheter 4, a second steady pressure curve 75 ismeasured. The duration 67 of the deviation 77 is the amount of transitof the particular significant pieces or portions 90 of thrombus 88. Theduration 67 can range quite a bit, but in some cases, may be less than asecond or up to about 30 seconds. A single thrombus being aspirated maycause a single decrease in pressure (a blip) which is identified by themeasurement device 54, 64. When again additional pieces or portions 90of thrombus 88 are aspirated into and travel down the aspiration lumen18 of the aspiration catheter 4, another deviation 73 of fluid pressurecomprising one or more decreases and increases in pressure (increasesand decreases in vacuum pressure) is measured. At the end of the curve79, the vacuum source 6 is shown filling completely with blood 96 andthe pieces or portions 90 of thrombus 88, and so an upward slope 95 ismeasured.

The measurement device 54, 64 is configured to compare the curve 79 withinformation stored in the memory module 56, 66 to identify when thepieces or portions 90 of thrombus 88 are actively being aspirated, as indeviation 77 and deviation 73, and when the pieces or portions ofthrombus 88 are not being actively, or substantially, aspirated, as insteady pressure curve 97, the steady pressure curve 75, and the steadypressure curve 71. In some embodiments, the measurement device 54, 64uses an algorithm to make the comparison. In some embodiments, a pre-setpressure differential ΔP₂ may be stored in the memory module 56, 66 as athreshold, whereby the measurement of a pressure difference 69 less thanthis threshold does not result in the measurement device 54, 64commanding the communication device 58 a-c, 74 to send a first type ofalert via an alert signal 60 a-c, 70. In some embodiments, when thepressure difference 69 is greater than (or greater than or equal to) thepre-set pressure differential ΔP₂, the measurement device 54, 64 thensends a signal to the communication device 58 a-c, 74, and thecommunication device 58 a-c, 74 generates an appropriate alert.Communication device 58 a, for example a particular color LED, may beilluminated, or an LED may flash in a particular pattern or number offlashes. In some embodiments, the communication device 58 a may comprisea light whose intensity increases proportionally with the pressure.Communication device 58 b may create a characteristic sound, or maygenerate an audio message in a number of languages. For example, theaudio message may state, “Thrombus being aspirated.” In someembodiments, communication device 58 b may comprise one or more noisesor beeps. In some embodiments, the communication device 58 b maycomprise a particular series of beeps corresponding to each differentcondition. For example, three short beeps may correspond to no thrombusbeing aspirated, while five long, loud beeps may correspond to a systemleak. In some embodiments, a plurality of different tones (pitches) maybe used to alert a user about different conditions. As an example, a lowpitch sound may be used for a first condition (e.g. no thrombus beingaspirated) and a second, higher pitch sound may be used for a secondcondition (e.g. a system leak). In some embodiments, a plurality ofdifferent tones may be used to alert a user about a first condition anda second plurality (e.g. in a different combination, or with additionaltones) may be used to alert a user about a second condition.Communication device 58 c may vibrate or heat in a characteristicpattern, for example, a certain number of repetitions or a certainfrequency between repetitions. When the user realizes that the thrombusis being aspirated, the user may choose to advance (or retract) theaspiration catheter 4, for example with fluoroscopic visualization,along the length of the thrombus 88, in an attempt to continue theaspiration of the thrombus 88. In some cases, the user may choose tostop the advancement or retraction of the aspiration catheter 4 at acertain amount of time after the alert is generated, in order to allowthe pieces or portions 90 of thrombus 88 to completely exit theaspiration lumen 18. When the measurement device 54, 64 identifies asubsequent steady pressure curve 75, 71 that follows a deviation 77, 73,the measurement device 54, 64 in some embodiments sends a signal thatcauses the communication device 58 a-c, 74 to generate a second type ofalert via an alert signal 60 a-c, 70. For example, in some embodiments,communication device 58 b may send an audio message that states,“Thrombus no longer being aspirated.” When the user realizes that thethrombus is no longer being aspirated, the user may advance or retractthe aspiration catheter, in an attempt to contact another portion of thethrombus 88 that can be aspirated. In some embodiments, the deviation 77may be positively identified as a true deviation indicating thrombusbeing actively aspirated, pressure difference 69 is between about 700pascal and about 1700 pascal. In some embodiments, the deviation 77 maybe positively identified as a true deviation indicating thrombus beingactively aspirated, pressure difference 69 is between about 1000 pascaland about 1300 pascal. In some embodiments, the deviation 77 may bepositively identified as a true deviation indicating thrombus beingactively aspirated, pressure difference 69 is about 1138 pascal. Thepressure difference 69 may be measured by determining a baselinepressure 63 and a peak pressure 61 and determining the absolute valuedifference. For example:Absolute value difference (AVD)=|(−89,631 pascal)−(−90,769 pascal)|=1138pascal

Or for example:Absolute value difference (AVD)=|(−43,710 pascal)−(−45,102 pascal)|=1281pascal

The pressure difference 81 (FIG. 5B) may also represent a deviation thatmay be identified in a similar manner, after which the communicationdevice 58 a-c, 74 generates an appropriate alert, such as, “Clogcondition.”

Because vacuum pressure is a negative pressure, the peak pressure 61, asshown in FIG. 5D, is actually a lower number than the baseline pressure63. In some embodiments, the measurement device 54, 64 may also beconfigured to make a comparison, for example by using an algorithm,between a stored differential time t₁ and a duration 65 of a single oneof the more or more decreases and increases in pressure in the deviation77. For example, in some embodiments, the deviation may be positivelyidentified as a true deviation indicating thrombus being activelyaspirated, if the duration is between about 0.001 seconds and about 0.50seconds. In some embodiments, the deviation may be positively identifiedas a true deviation indicating thrombus being actively aspirated, if theduration is between about 0.005 seconds and about 0.10 seconds. In someembodiments, the deviation may be positively identified as a truedeviation indicating thrombus being actively aspirated if the durationis between about 0.05 seconds and about 0.20 seconds. In someembodiments, the measurement device 54, 64 is configured to recognizedeviation 77 after two or more decreases and increases in pressure aremeasured. In some embodiments, the measurement device 54, 64 isconfigured to recognize deviation 77 after five or more decreases andincreases in pressure are measured. In some embodiments, the measurementdevice 54, 64 is configured to recognize deviation 77 after ten or moredecreases and increases in pressure are measured.

Insertion of the pressure transducer 12 in line in either the embodimentof FIG. 2A or the embodiment of FIG. 2B does not measurably changeperformance characteristics of the aspiration system 2, because thecavity 42 is relatively short and has a relatively large inner diameter,and thus is not a significant source of fluid flow resistance. In someembodiments, the inner diameter may be between about 2.2 mm (0.086inches) and about 3.2 mm (0.125 inches). In some embodiments, themeasurement device 54, 64, 76 need not include a microprocessor, aspre-defined set points (e.g. for certain thresholds) may be included infirmware, microcontroller, or other locations. In some embodiments,including but not limited to the embodiment of FIG. 2B, the pressuretransducer 12 may be an off-the-shelf blood pressure monitor system,which is modified or augmented with other components. In someembodiments an off-the-shelf blood pressure monitor system may be usedas the output of the aspiration monitoring system 48, 62, 78. In someembodiments, an aspiration catheter 4 may have a pressure transducer inthe distal end 16. This pressure transducer may be used as the pressuretransducer 12 of the aspiration monitoring system 48, 62, 78. In someembodiments, a pressure sensor may be located within a Tuohy-Borstvalve, and introducer sheath, a guiding catheter, or another componentof the system through which is in fluid communication with theaspiration lumen 18. In some embodiments, the pressure sensor may belocated anywhere within the aspiration lumen of the aspiration catheter.

In some embodiments, instead of an LED, the visual alert is provided bya communication device 58 a comprising a display which displays visualmessages of text in a particular language, for example, “Thrombusencountered,” “No thrombus encountered,” “Clog condition,” “Systemleak,” “Loss of vacuum,” “Thrombus being aspirated,” or “Thrombus nolonger being aspirated.” The visual messages may be combined with any ofthe other alert signals 60 a-c, 70 described herein. The aspirationmonitoring system 48, 62, 78 described herein give real time awarenessto users performing aspiration procedures, such as the removal ofthrombus via an aspiration system 2. One skilled in the art willrecognize that by knowing the real time condition of the aspirationsystem 2, the user is able to immediately make changes to the procedurein order to optimize results, increase safety for the patient and/ormedical personnel, reduce costs (e.g. number of vacuum sources 6required), and reduce procedure time (also a cost benefit). Because theuser is typically performing multiple tasks during an aspirationprocedure, the sensory aid provided by the aspiration monitoring system48, 62, 78 allows the user to focus on these tasks without having tocontinually attempt to monitor conditions which are often difficult tovisually monitor. The user may also modify and control the aspirationmonitoring system 48, 62, 78 via an input 59 (FIG. 2B), which maycomprise a data entry module, keyboard, or a series of buttons with adisplay. The input 59 may in some embodiments comprise an auditory inputwhich accepts voice commands. Alternatively, the user may inputinformation and control the aspiration monitoring system, 48, 62, 78remotely. Some of the alerts which the user may select or deselect inthe aspiration monitoring system 48, 62, 78 include, but are not limitedto: whether the aspiration system 2 is potentially blocked or clogged,or is flowing normally; whether thrombus has been contacted or not;whether a clog has occurred; whether the vacuum source 6 is adequate, orwhether it has been depleted and requires replacement; whether there isa leak in the aspiration system 2; whether setup or connection of thecomponents of the aspiration system 2 was done correctly or incorrectly;whether to advance the catheter distally; whether to retract thecatheter; whether to continue moving the catheter at the same speed;whether to increase or decrease the speed of catheter advancement;whether thrombus is actively being aspirated; and whether thrombus stopsbeing actively aspirated. As the user becomes familiar with theaspiration monitoring system 48, 62, 78, the user may even begin to makecertain responses to the system subconsciously. For example, a user mayautomatically pull back the catheter upon hearing a clot warning signal(e.g., three beeps), and may automatically begin advancing the catheterand/or start fluoroscopic visualization upon hearing a free blood flowsignal (e.g., two beeps). By being “at one” with the aspirationmonitoring system 48, 62, 78 and the catheter, the user optimizesreactions and actions. This may be helpful improving the skill of havingthe catheter take a small “bite” of thrombus, and following the “bite”with a “chaser” of some fast flowing blood, the clean/open the lumen.This would also help minimize the chance of clogging, and would in turnreduce maintenance or corrections of the system (removing the catheter,flushing the lumen outside of the patient, replacing the catheter). Theoverall experience for the user is improved, as the user receivedinstant gratification for good results, and is instantly notified oferrors or instances for concern.

In some embodiments, alternate power sources may be used, for example,standard AC power with or without an AC/DC convertor; direct connectionto existing equipment (e.g. vacuum pumps, etc.); solar power. Theaspiration monitoring system 48, 62, 78 may be packaged sterile or maybe resterilizable by techniques known by those skilled in the art. Insome embodiments, flow or volume gauges may be used in conjunction withor instead of the pressure gauge 12, in order to determine, for example,a clog, or a change in the amount of vacuum. In some embodiments, theinput 59, power module 72, measurement device 64, memory module 66, andcommunication device 64 (e.g., of FIG. 2B) may all be incorporated intoa single external device, which may in some cases be sold separately. Insome embodiments, the external device may also have other functions,such as providing aspiration and/or injection (negative pressure and/orpositive pressure) to a catheter. In other embodiments, the externaldevice may comprise some, but not all of the input 59, power module 72,measurement device 64, memory module 66, and communication device 68.For example, in some embodiments, a communication device 58 (FIG. 2A)may replace the external communication device 68, and may be carried onthe aspiration monitoring system 48, while the input 59, power module72, measurement device 64, memory module 66 (FIG. 2B) are incorporatedinto a single external device. A number of combinations are possible, asdescribed in more detail herein.

Though aspiration of thrombus has been described in detail, theaspiration monitoring system 48, 62, 78 has utility in any aspirationapplication wherein heterogeneous media is being aspirated. This mayinclude the aspiration of emboli (including not thrombotic emboli) fromducts, vessels, or cavities of the body, or even from solid orsemi-solid portions of the body, including, but not limited to, portionsof fat, breasts, and cancerous tissue.

In some embodiments, the aspiration system 2 is be provided to the useras a kit with all or several of the components described, while in otherembodiments, only the aspiration monitoring system 48 is provided.Though discussion herein includes embodiments for aspiration of thrombusand blood, the definition of the word “fluid” should be understoodthroughout to comprise liquids and gases.

In some embodiments, an additional or alternate sensor may be used tomonitor flow conditions for the notification of the user, including, butnot limited to: a Doppler sensor, an infrared sensor, or a laser flowdetection device. In some embodiments, an externally-attached Dopplersensor may be employed. In some embodiments, an infrared sensor or alaser flow detection device may be employed around the extension tubing10.

Additional embodiments allow real time communication of the particularvalue of fluid pressure (for example the level of vacuum) measured bythe sensor 50. For example, as the amount of vacuum increases, anaudible sound may increase in sound intensity or in sound pressure level(dB) proportionally. Or, as the amount of vacuum increases, the pitch(frequency) of an audible sound may made to rise, and as the amount ofvacuum decreases, the pitch may be made to fall (as does a siren). Bycontrolling either the amplitude of a signal or the frequency of asignal by making them proportional to the fluid pressure, the system cangive a user a real-time sense of whether the vacuum is increasing,decreasing, or staying the same, as well as whether the pressure isclose to zero or quite different from zero. When an audible sound isused as the signal, the users eyes can remain focused on the procedure,whether by viewing a monitor of fluoroscopic images, the patient, or aseparate piece of equipment.

FIG. 6 illustrates a graph 800 of time (x-axis) and multiple variables(y-axis). A pressure curve 802 shows a vacuum being applied at apressure drop 808, and a maintenance of vacuum 810 a with a decrease invacuum 812 and an increase in vacuum 814. A removal of vacuum 816 isshown at the end of the pressure curve 802. In some cases, the decreasein vacuum 812 may be caused by a temporary or permanent leak ordetachment within the system or by filling of the vacuum source (e.g.,syringe). In FIG. 6, the decrease in vacuum 812 is shown as temporary,as a subsequent maintenance of vacuum 810 b is illustrated. The increasein vacuum 814 may in some cases be caused by thrombus being suckedthrough the system and may occur for a short or long amount of time, andmay be steady or intermittent. Though the amount of vacuum applied inthe pressure curve 802 varies, in some embodiments, it may only bedesirable to show to a user only whether the vacuum is generally beingapplied or not being applied. The measurement device 54, 64, 76 may beconfigured to apply an algorithm to the signal from the vacuum sensor 50(pressure sensor) that calculates an inverse value, represented by thedashed curve 804. The measurement device 54, 64, 76 further may apply analgorithm that increases, amplifies or otherwise augments the signal forease of identification, for example within the human range of audibleidentification (hearing). For example, a modified signal curve 806 maybe created that has the following general mathematical relationship withthe signal from the vacuum sensor 50 represented by the pressure curve802.Sound Pressure Level (dB)=A+B×(1/fluid pressure)

-   -   where A is a first constant, and    -   B is a second constant

In one particular example, a modified signal curve 806 may be createdthat has the following mathematical relationship with the signal fromthe vacuum sensor 50 represented by the pressure curve 802.Sound Pressure Level (dB)=70+20×(1/fluid pressure (kPa))

-   -   where dB is units in decibels, and    -   kPa is units of kiloPascal

The modified signal curve 806 may be constructed of an algorithm suchthat the sound pressure level drops below the audible level of humanhearing at relatively small amounts of vacuum, thus giving the user an“on/off” awareness of the vacuum being applied.

FIG. 7 illustrates a graph 820 of time (x-axis) and multiple variables(y-axis). A pressure curve 822 shows a vacuum being applied at apressure drop 828, and a maintenance of vacuum 830 a with a decrease invacuum 832 and an increase in vacuum 834. A removal of vacuum 836 isshown at the end of the pressure curve 822. In some cases, the decreasein vacuum 832 may be caused by a temporary or permanent leak ordetachment within the system or by filling of the vacuum source (e.g.,syringe). In FIG. 7, the decrease in vacuum 832 is shown as temporary,as a subsequent maintenance of vacuum 830 b is illustrated. The increasein vacuum 834 may in some cases be caused by thrombus being suckedthrough the system and may occur for a short or long amount of time, andmay be steady or intermittent. In some cases or configurations, it maybe desirable for the user to have a very specific real-time or close toreal-time characterization of the amount or level of vacuum (or pressurein general) being applied. The measurement device 54, 64, 76 may beconfigured to apply an algorithm to the signal from the vacuum sensor 50(pressure sensor) that calculates an absolute value, represented by thedashed curve 824. The measurement device 54, 64, 76 further may apply analgorithm that increases, amplifies or otherwise augments the signal forease of identification, for example within the human range of audibleidentification (hearing). For example, a modified signal curve 826 maybe created that has the following general mathematical relationship withthe signal from the vacuum sensor 50 represented by the pressure curve822.Sound Pressure Level (dB)=A+B×|(fluid pressure)|

-   -   where A is a first constant, and    -   B is a second constant

In one particular example, a modified signal curve 826 may be createdthat has the following mathematical relationship with the signal fromthe vacuum sensor 50 represented by the pressure curve 822.Sound Pressure Level (dB)=2×|(fluid pressure (kPa))|

-   -   where dB is units in decibels and,    -   kPa is units of kiloPascal

The modified signal curve 826 may be constructed of an algorithm suchthat the sound pressure level seems to the user to follow the amount ofvacuum being applied.

FIG. 8 illustrates a graph 840 of time (x-axis) and multiple variables(y-axis). A pressure curve 842 shows a vacuum being applied at apressure drop 848, and a maintenance of vacuum 850 a with a decrease invacuum 852 and an increase in vacuum 854. A removal of vacuum 856 isshown at the end of the pressure curve 842. In some cases, the decreasein vacuum 852 may be caused by a temporary or permanent leak ordetachment within the system or by filling of the vacuum source (e.g.,syringe). In FIG. 8, the decrease in vacuum 852 is shown as temporary,as a subsequent maintenance of vacuum 850 b is illustrated. The increasein vacuum 854 may in some cases be caused by thrombus being suckedthrough the system and may occur for a short or long amount of time, andmay be steady or intermittent. As mentioned, in some cases orconfigurations, it may be desirable for the user to have a very specificreal-time or close to real-time characterization of the amount or levelof vacuum (or pressure in general) being applied. The measurement device54, 64, 76 may be configured to apply an algorithm to the signal fromthe vacuum sensor 50 (pressure sensor) that calculates an absolutevalue, represented by the dashed curve 844. The measurement device 54,64, 76 further may apply an algorithm that determines a frequency of anaudible sound (or pitch), for example within the human range of audibleidentification (hearing), that varies within the human range of audiblefrequencies. For example, a modified signal curve 846 may be createdthat has the following general mathematical relationship with the signalfrom the vacuum sensor 50 represented by the pressure curve 842.Sound Frequency (Hz)=A+B×|(fluid pressure)|

-   -   where A is a first constant, and    -   B is a second constant

In one particular example, a modified signal curve 846 may be createdthat has the following mathematical relationship with the signal fromthe vacuum sensor 50 represented by the pressure curve 842.Sound Frequency (Hz)=50×|(fluid pressure (kPa))|

-   -   where Hz is Hertz (1/second), and    -   kPa is units of kiloPascal

The modified signal curve 846 may be constructed of an algorithm suchthat the sound frequency seems to the user to follow the amount ofvacuum being applied. In this embodiment, the pitch of the sound becomes“higher” when vacuum is increased (fluid pressure decreases), and“lower” when the vacuum is decreased. Alternatively, the opposite mayinstead by chosen, wherein the pitch of the sound becomes lower whenvacuum is increased.

FIG. 9 illustrates a graph 860 of time (x-axis) and multiple variables(y-axis). A pressure curve 862 shows a vacuum being applied at apressure drop 868, and a maintenance of vacuum 870 with one or moredecreases and increases in pressure 872. These decreases and increasesin pressure (or increases and decreases in vacuum) may represent, insome instances, clot being sucked through aspiration lumen of anaspiration catheter. In some cases, a single decrease in pressure 873(increase in vacuum) may occur. The single decrease in pressure 873 mayin some cases be extended in duration, as shown in FIG. 9, as may anyone of the one or more decreases and increases in pressure 872. In somecases or configurations, it may be desirable for the user to have a veryspecific real-time or close to real-time characterization of theinstances when these small perturbations are occurring, as they maycorrespond to the catheter finding and aspirating a portion of thrombus.The measurement device 54, 64, 76 be configured to apply an algorithmthat determines a frequency of an audible sound (or pitch), for examplewithin the human range of audible identification (hearing), that varieswithin the human range of audible frequencies. For example, a modifiedsignal curve 866 may be created that has the following generalmathematical relationship with the signal from the vacuum sensor 50represented by the pressure curve 862.Sound Frequency (Hz)=A+B×(fluid pressure)

-   -   where A is a first constant, and    -   B is a second constant

In one particular example, a modified signal curve 866 may be createdthat has the following mathematical relationship with the signal fromthe vacuum sensor 50 represented by the pressure curve 862.Sound Frequency (Hz)=40×(fluid pressure (kPa))

-   -   where Hz is Hertz (1/second), and    -   kPa is units of kiloPascal

It should be noted that in this equation, no absolute value is used, butrather the actual value of fluid pressure.

The modified signal curve 866 may be constructed of an algorithm suchthat the sound maintains a steady pitch until the clot is being suckedthrough the catheter, at which time the pitch changes slightly, butdistinctly, away from a steady pitch. For example, in some embodiments,the pitch may change between about 20 Hz and about 2000 Hz to correspondto a pressure change of between about one kPa to about two kPa, orbetween about 40 Hz and about 80 Hz.

In any of the examples, the modification of signals may include any typeof signal conditioning or signal modification that may be performed,including, but not limited to filtering, amplification, or isolation.The modified signal curve 806, 826, 846, 866 is used to determine theoutput signal to be generated by the communication device 58, 68, 74. Asmentioned, if the output signal of the communication device 58, 68, 74is configured to be an audible sound, the sound pressure level may bevaried, or the sound frequency may be varied. In some embodiments, othercharacteristics of psychoacoustics may be varied using variable soundgeneration devices. In some embodiments, the spectral envelope may bevaried. In come embodiments, timbre may be changed to varies levelsbetween light and dark, warm and harsh, or different noise “colors”(pink, white, blue, black, etc.).

Though an audible output from the communication device 58, 68, 74 hasbeen described with the examples from FIGS. 6-9, other communicationsignals may be used, including visual or tactile signals. Tactilesignals may also include vibration devices or heat generation devices,either of which could be varied (as described) in relation to themeasured fluid pressure. Either the amplitude of the frequency couldanalogously be varied in communication signals that include signalsother than the audible signals already described. For example, theintensity of a light can be varied, or the frequency (e.g., color) of alight can be varied. The amplitude of displacement of a vibration devicecan be varied (or other techniques that vary the vibration intensity) orthe frequency of the vibration can be varied.

In some cases, a pseudo-continuous analog may be used in place of atruly variable output. For example, instead of a single light whoseintensity is continuously varied, an array of multiple lights, forexample and array comprising multiple LEDs, may be used, with anincreased number of LEDs being lit when the level of vacuum isincreased. The same may be possible with an array comprising multiplevibrating elements, wherein more elements begin vibrating upon anincrease or decrease, depending on the application, of fluid pressure.

A pressure transducer 912 of an aspiration monitoring system 900 isillustrated in FIG. 10, for coupling to an aspiration system includingan aspiration catheter 4. The pressure transducer 912 includes a housing40, a first port 44, a second port 46 and a cable 902 for carrying asignal. The cable 902 includes an interface 904, or plug, which isconfigured to connect to a port 906 of a console 908 of the aspirationmonitoring system 900. The housing 40 of the pressure transducer 912includes a cavity 42 extending between the first port 44 and the secondport 46. The console 908 is powered by a power module 972, which isconnected to the console 908, and may comprise a source of AC or DCpower. The console 908 may include a measurement device 964, a memorymodule 966 and a communication device 968, which may be coupled coupledto each other as described in the prior embodiments and configured suchthat the communication device 968 is capable of creating a signal 970,which may be an alert signal, a continuous signal or other type ofsignal. The console 908 may also include wired or wireless connectionsto other interfaces or displays which may be found in health care sites,such as a monitor 931. In some embodiments, the monitor 931 may be amonitor which also displays fluoroscopy or angiogram images, or amonitor which also displays electrocardiography or blood pressuregraphics or other information. The monitor 931 may have a portion thatmaintains the status of the aspiration. For example, it may read“Thrombus being aspirated” or “No thrombus detected.” The pressuretransducer 912 (housing 40, ports 44, 46, cable 902, interface 904) maybe sold sterile, and may be configured to output a signal that isreceived by the console 908, for example the measurement device 964 ofthe console 908. The pressure transducer 912 may have its own internalsource of power (e.g., the battery 52 in FIG. 2A), or may be powered byits connection to the console 908, or alternatively, by its connectionto the aspiration catheter 4, or even the extension tubing 10. In someembodiments, the console 908 may be configured to identify and/orrecognize the pressure transducer 912, for example, to recognize theparticular model of the pressure transducer 912. In some embodiments,the console 908 may be configured to measure a resistance between twoelectrical contacts in the pressure transducer 912 in order to identifythe type (e.g., model) of pressure transducer. In some embodiments, theconsole 908 may be configured to read an RFID chip on the pressuretransducer 912. The console 908 may also be configured to connect to twoor more different models of pressure transducer. For example. The port906, may comprise at least one port, which may comprise two or moreports, each port configured to allow connection of a different model ofpressure transducer.

An aspiration system 1000 in FIG. 11 includes an aspiration console 1001having a connector 1002, or hub, (e.g., male luer) for connecting to anaspiration catheter 4, for example, to a connector 22 (e.g., femaleluer) of the aspiration catheter 4. The aspiration console 1001 ispowered by a power module 972, which is connected to the aspirationconsole 1001, and may comprise a source of AC or DC power. Theaspiration console 1001 may include a canister 1006 for collecting theaspirated materials, and may include a vacuum pump 1004 for creating avacuum with which to create the aspiration. Tubing 1008 may be connectedbetween the canister 1006 and the connector 1002. In some embodiments,the canister 1006 is removable or replaceable. An aspiration monitoringsystem 900 includes a pressure sensor 1010 (e.g., a vacuum sensor) influid communication with the tubing 1008. The tubing 1008 may instead beformed of a lumen formed inside fabricated parts. The aspirationmonitoring system 900 is shown in more detail in FIG. 12, and mayinclude some or all of the features described in relation to FIG. 10.The aspiration console 1001 may also include wired or wirelessconnections to other interfaces or displays which may be found in healthcare sites, such as a monitor 931. In some embodiments, the monitor 931may be a monitor which also displays fluoroscopy or angiogram images, ora monitor which also displays electrocardiography or blood pressuregraphics or other information. By combining all communication related tothe procedure on or at a single monitor or single monitor location,uninterrupted focus can be achieved by the user, who may be freelydedicated to the safe advancement and placement of the aspirationcatheter in proximity to the thrombus.

A system for forced (or assisted) aspiration 1100 in FIG. 13 includes anaspiration/injection console 1101 having a first connector 1016, or hub,(e.g., male luer) for connecting to an injection lumen 1020 of a forcedaspiration catheter 1013, and a second connector 1012, or hub (e.g.,male luer) for connecting to an aspiration lumen 1018 of the forcedaspiration catheter 1013. The first connector 1016 is configured toconnect to connector 1024 (e.g., female luer) of a y-connector 1022 andthe second connector 1012 is configured to connect to connector 1026 ofthe y-connector 1022 at a proximal end 14 of the forced aspirationcatheter 1013. The aspiration/injection console 1101 is powered by apower module 972, which is connected to the aspiration console 1101, andmay comprise a source of AC or DC power. The aspiration console 1101 mayinclude a canister 1106 for collecting the aspirated materials, and mayinclude a vacuum pump 1104 for creating a vacuum with which to createthe aspiration. Tubing 1108 may be connected between the canister 1106and the connector 1012. A positive pressure pump 1014 is coupled to afluid source 1032 (e.g., a saline bag) and is configured to injectinfusate out the connector 1016 at a high pressure. An aspirationmonitoring system 900 includes a pressure sensor 1110 (e.g., a vacuumsensor) in fluid communication with the tubing 1108. The tubing 1108 mayinstead be formed of a lumen formed inside fabricated parts. Theaspiration monitoring system 900 is shown in more detail in FIG. 14, andmay include some or all of the features described in relation to FIG.10. At a distal end 16 of the forced aspiration catheter 1013, theinjection lumen 1020 terminates in an orifice 1028, which is configuredto create a jet 1030 formed from the high pressure infusate exiting theorifice 1028. The jet 1030 enters the aspiration lumen 1018, thuscreating suction at the distal end 16 of the forced aspiration catheter1013, which forces materials (e.g., thrombus) into the aspiration lumen1018, and into the canister 1106. The aspiration/injection console 1101may also include wired or wireless connections to other interfaces ordisplays which may be found in health care sites, such as a monitor 931.In some embodiments, the monitor 931 may be a monitor which alsodisplays fluoroscopy or angiogram images, or a monitor which alsodisplays electrocardiography or blood pressure graphics or otherinformation.

In an alternative embodiment, the forced aspiration catheter 1013 of theaspiration catheter 4 may have an additional lumen or guide channel forplacement of an additional device or tool. In some embodiments, theguidewire lumen 26 may be used as this additional lumen, and may extendthe entire length or most of the length of the catheter, so that thelumen is accessible from the proximal end 14. The additional device ortool may comprise a laser fiber, a mechanical screw, a vibrating wire ora variety of other modalities for disrupting thrombus or other material.

FIG. 15 is a diagrammatic figure depicting an assisted aspiration system510. The aspiration system 510 includes a remote hand piece 512 thatcontains a fluid pump 526 and an operator control interface 506. In onecontemplated embodiment, the system 510 is a single use disposable unit.The aspiration system 510 may also include extension tubing 514, whichcontains a fluid irrigation lumen 502 and an aspiration lumen 504, andwhich allows independent manipulation of a catheter 516 withoutrequiring repositioning of the hand piece 512 during a procedureperformed with the aspiration system 510. Extension tubing 514 may alsoact as a pressure accumulator. High pressure fluid flow from the pump526, which may comprise a displacement pump, pulses with each stroke ofthe pump 526 creating a sinusoidal pressure map with distinct variationsbetween the peaks and valleys of each sine wave. Extension tubing 514may be matched to the pump 526 to expand and contract in unison witheach pump pulse to reduce the variation in pressure caused by the pumppulses to produce a smooth or smoother fluid flow at tip of catheter516. Any tubing having suitable compliance characteristics may be used.The extension tubing 514 may be permanently attached to the pump 526 orit may be attached to the pump 526 by a connector 544. The connector 544is configured to ensure that the extension tubing 514 cannot be attachedto the pump 526 incorrectly.

An interface connector 518 joins the extension tubing 514 and thecatheter 516 together. In one contemplated embodiment, the interfaceconnector 518 may contain a filter assembly 508 between high pressurefluid injection lumen 502 of the extension tubing 514 and a highpressure injection lumen 536 of the catheter 516 (FIG. 17). The catheter516 and the extension tubing 514 may be permanently joined by theinterface connector 518. Alternatively, the interface connector 518 maycontain a standardized connection so that a selected catheter 516 may beattached to the extension tubing 514. In some embodiments, the filterassembly 508 may be removably coupled to the extension tubing 514 by aquick disconnect connection. A pressure transducer of an embodiment ofthe aspiration monitoring system presented herein may be located at apoint along the aspiration lumen 504 or any extension of the aspirationlumen 504.

Attached to the hand piece 512 are a fluid source 520 and a vacuumsource 522. A standard hospital saline bag may be used as fluid source520; such bags are readily available to the physician and provide thenecessary volume to perform the procedure. Vacuum bottles may providethe vacuum source 522 or the vacuum source 522 may be provided by asyringe, a vacuum pump or other suitable vacuum source. The filterassembly 508 serves to filter particulate from the fluid source 520 toavoid clogging of the high pressure injection lumen 536 and an orifice542 (FIG. 17). As described herein, distal sections of the high pressureinjection lumen 536 may be configured with small inner diameters, and tothe filter assembly 508 serves to protect their continuing function. Byincorporating one of a variety of catheters 516 into the assistedaspiration system 510, for example with varying lumen configurations(inner diameter, length, etc.), a variety of aspiration qualities(aspiration rate, jet velocity, jet pressure) may be applied in one ormore patients. These aspiration qualities can be further achieved byadjustment of the pump 526, to modify pump characteristics (flow rate,pump pressure). In some embodiments, the catheter 516 may be usedmanually, for example, without the pump 526, and controlled by handinjection. The manual use of the catheter 516 may be appropriate forcertain patient conditions, and may serve to reduce the cost of theprocedure.

In one contemplated embodiment, the catheter 516 has a variablestiffness ranging from stiffer at the proximal end to more flexible atthe distal end. The variation in the stiffness of the catheter 516 maybe achieved with a single tube with no radial bonds between two adjacenttubing pieces. For example, the shaft of the catheter 516 may be madefrom a single length of metal tube that has a spiral cut down the lengthof the tube to provide shaft flexibility. Variable stiffness may becreated by varying the pitch of the spiral cut through different lengthsof the metal tube. For example, the pitch of the spiral cut may begreater (where the turns of the spiral cut are closer together) at thedistal end of the device to provide greater flexibility. Conversely, thepitch of the spiral cut at the proximal end may be lower (where theturns of the spiral cut are further apart) to provide increasedstiffness. A single jacket covers the length of the metal tube toprovide for a vacuum tight catheter shaft. Other features of catheter516 are described with reference to FIG. 17, below.

FIG. 16 is a diagrammatic view showing more detail of the hand piece 512and the proximal portion of assisted catheter aspiration system 510. Thehand piece 512 includes a control box 524 where the power and controlsystems are disposed. The pump 526 may be a motor driven displacementpump that has a constant output. This pump displacement to cathetervolume, along with the location of the orifice 542 (exit) of thecatheter high pressure lumen 536 within the aspiration lumen 538 (FIG.17), ensures that no energy is transferred to the patient from thesaline pump as all pressurized fluid is evacuated by the aspirationlumen. A prime button 528 is mechanically connected to a prime valve530. When preparing the device for use, it is advantageous to evacuateall air from the pressurized fluid system to reduce the possibility ofair embolization. By depressing the prime button 528, the user connectsthe fluid source 520 to the vacuum source 522 via the pump 526. Thisforcefully pulls fluid (for example 0.9% NaCl solution, or “saline”, no“normal saline”, or heparinized saline) through the entire pump system,removing all air and positively priming the system for safe operation. Apressure/vacuum valve 532 is used to turn the vacuum on and offsynchronously with the fluid pressure system. One contemplated valve 532is a ported one way valve. Such a valve is advantageous with respect tomanual or electronic valve systems because it acts as a tamper proofsafety feature by mechanically and automatically combining theoperations of the two primary systems. By having pressure/vacuum valve532, the possibility of turning the vacuum on without activating thefluid system is eliminated.

The operator control interface 506 is powered by a power system 548(such as a battery or an electrical line), and may comprise anelectronic control board 550, which may be operated by a user by use ofone or more switches 552 and one or more indicator lamps 554. Thecontrol board 550 also monitors and controls several device safetyfunctions, which include over pressure and air bubble detection andvacuum charge. A pressure sensor 564 monitors pressure, and senses thepresence of air bubbles. Alternatively, an optical device 566 may beused to sense air bubbles. In one contemplated embodiment, the pumppressure is proportional to the electric current needed to produce thatpressure. Consequently, if the electric current required by pump 526exceeds a preset limit, the control board will disable the pump bycutting power to it. Air bubble detection may also be monitored bymonitoring the electrical current required to drive the pump at anyparticular moment. In order for a displacement pump 526 to reach highfluid pressures, there should be little or no air (which is highlycompressible) present in the pump 526 or connecting system (includingthe catheter 516 and the extension tubing 514). The fluid volume issmall enough that any air in the system will result in no pressure beinggenerated at the pump head. The control board monitors the pump currentfor any abrupt downward change that may indicate that air has enteredthe system. If the rate of drop is faster than a preset limit, thecontrol board will disable the pump by cutting power to it until theproblem is corrected. Likewise, a block in the high pressure lumen 536,which may be due to the entry of organized or fibrous thrombus, or asolid embolus, may be detected by monitoring the electrical currentrunning the pump 526. In normal use, the current fluxuations of the pump526 are relatively high. For example, the pump may be configured so thatthere is a variation of 200 milliAmps or greater in the current duringnormal operation, so that when current fluxuations drop below 200milliAmps, air is identified, and the system shuts down. Alternatively,current fluxuations in the range of, for example, 50 milliAmps to 75milliAmps may be used to identify that air is in the system.Additionally, an increase in the current or current fluxuations mayindicate the presence of clot or thrombus within the high pressure lumen536. For example, a current of greater than 600 milliAmps may indicatethat thrombus it partially or completely blocking the high pressurelumen 536, or even the aspiration lumen 538.

A vacuum line 556, connected to the vacuum source 522, may be connectedto a negative pressure sensor 558. If the vacuum of the vacuum source522 is low or if a leak is detected in the vacuum line 556, the controlboard 550 disables the pump 526 until the problem is corrected. Thenegative pressure sensor 558 may also be part of a safety circuit 560that will not allow the pump 526 to run if a vacuum is not present.Thereby a comprehensive safety system 562, including the safety circuit560, the pressure sensor 564 and/or the optical device 566, and thenegative pressure sensor 558, requires both pump pressure and vacuumpressure for the system to run. If a problem exists (for example, ifthere is either a unacceptably low pump pressure or an absence ofsignificant vacuum), the control board 550 will not allow the user tooperate the aspiration system 510 until all problems are corrected. Thiswill keep air from being injected into a patient, and will assure thatthe aspiration system 510 is not operated at incorrect parameters.

FIG. 17 is a diagrammatic view of the distal end portion 568 of theassisted catheter aspiration system 510, showing more details of thecatheter 516. The catheter 516 is a single-operator exchange catheterand includes a short guidewire lumen 534 attached to the distal end ofthe device. The guidewire lumen 534 can be between about 1 and about 30cm in length, or between about 5 and about 25 cm in length, or betweenabout 5 and about 20 cm in length, or approximately 13.5 cm in length.An aspiration lumen 538 includes a distal opening 540 which allows avacuum (for example, from vacuum source 522) to draw thrombotic materialinto the aspiration lumen 538. A high pressure lumen 536 includes adistal orifice 542 that is set proximally of distal opening 540 by a setamount. For example, distal orifice 42 can be set proximally of distalopening 540 by about 0.0508 cm (0.020 inches), or by 0.0508 cm±0.00762cm (0.020 inches±0.003 inches) or by another desired amount. The orifice542 is configured to spray across the aspiration lumen to macerateand/or dilute the thrombotic material for transport to vacuum source522, for example, by lowering the effective viscosity of the thromboticmaterial. The axial placement of the fluid orifice 542 is such that thespray pattern interaction with the opposing lumen wall produces a spraymist and not a swirl pattern that could force embolic material out fromthe distal opening 540. The system may be configured so that theirrigation fluid leaves the pump at a pressure of between about3,447,378 pascal (500 psi) and about 10,342,135 pascal (1500 psi). Insome embodiments, after a pressure head loss along the high pressurelumen 536, the irrigation fluid leaves orifice 542 at between about4,136,854 pascal (600 psi) and about 8,273,708 pascal (1200 psi), orbetween about 4,481,592 pascal (650 psi) and about 5,860,543 pascal (850psi). In some cases, it may be possible (and even desired) to use theassisted catheter aspiration system 510 without operating the pump 526,and thus use the catheter 516 while providing, for example, a handsaline injection via a syringe. Or, in some cases, the assisted catheteraspiration system 510 may be used without the pump 526 attached, withthe saline injections done by hand using a syringe through the highpressure lumen 536. If a clog occurs, the syringe may be removed and thepump 526 attached and initiated, for example, for the purpose ofunclogging the high pressure lumen 536.

When normal blood flow is achieved after unblocking occlusions orblockages from atherosclerotic lesions and/or thrombosis, there issometimes a risk of reperfusion injury. This may be particularlysignificant following thrombectomy of vessels feeding the brain fortreatment of thromboembolic stroke, or following thrombectomy ofcoronary vessels feeding the myocardium. In the case of therevascularization of myocardium following a coronary intervention (e.g.thrombectomy). Reperfusion injury and microvascular dysfunction may bemechanisms that limit significant or full recovery of revascularizedmyocardium. The sudden reperfusion of a section of myocardium that hadpreviously been underperfused may trigger a range of physiologicalprocesses that stun or damage the myocardium. Distal coronary emboli,such as small portions of thrombus, platelets and atheroma, may alsoplay a part. Controlled preconditioning of the myocardium at risk hasbeen proposed to limit the effect of reperfusion injury andmicrovascular dysfunction. The embodiments of the thrombectomy systems100, 300 presented herein may be combined with additional features aimedat allowing flow control, in order to limit the potential dangers due toreperfusion following thrombectomy. Other contemplated embodiments of anassisted aspiration system 510 which may be utilized are disclosed inU.S. Patent Application No. 2010/0094201 to Mallaby (“Mallaby”)published Apr. 15, 2010, which is incorporated herein by reference inits entirety for all purposes. Other contemplated catheters aredisclosed in U.S. Patent Application No. 2008/0255596 to Jenson et al.(“Jenson”) published Oct. 16, 2008, which is incorporated herein byreference in its entirety for all purposes.

In any of the embodiments presented, the system may be configured sothat most or all of the components are supplied together. For example, acatheter and an aspiration monitoring system that are permanentlyattached to each other. In some embodiments, the aspiration catheterand/or the aspiration monitoring system may include configurations thatpurposely make it difficult to reprocess (e.g., clean or resterilize)them, thus protecting from potential uses that are not recommended orwarranted, and which may risk patient infection and/or devicemalfunction. For example, the sensor or the portion adjacent the sensormay be purposely difficult to access or clean. Alternatively, one ormore batteries may be impossible to access or change.

In some embodiments, it may be desired to have other descriptivewarnings that can be tied to pressure measurement or pressuremeasurement combined with another measured attribute. For example, if asensor (accelerometer or temperature sensor) within the aspirationcatheter is used to detect catheter movement, a change in this sensormay be tied to the pressure sensor. In this manner, a catheter that isengaged with a thrombus at its tip and is moved (e.g., begins to bepulled out of the patient) may then cause a warning: “Warning, do notmove catheter; risk of thromboembolus.”

FIG. 18 illustrates a multi-purpose system 1200 comprising amulti-purpose catheter 1202 having an infusion/injection port 1204 andan aspiration port 1206. The infusion/injection port 1204 and theaspiration port 1206 may each comprise luer connectors, such as femaleluer lock connectors. A tubing set 1208 and a pressure sensor 1210 areconnected in line with a vacuum source 1212. A cable 1214 carriessignals from the pressure sensor 1210 to an aspiration monitoring system1216, and connects to the aspiration monitoring system 1216 via aninterface 1218, or plug, which is configured to connect to a port 1220of a console 1222 of the aspiration monitoring system 1216 (FIG. 19).Apparati and methods described herein may be used to monitor aspirationusing the aspiration monitoring system 1216. In one manner of use asyringe 1224 (FIG. 18) may be used to manually inject through aninjection port 1204 and injection lumen (e.g., high pressure lumen) ofthe multi-purpose catheter 1202. The injection lumen in some embodimentsmay be configured for injection of saline at a relatively high pressure,or at either high or low pressures. If the valve 1226, or stopcock, isclosed, blocking the vacuum source 1212 from applying a vacuum to theaspiration lumen via the aspiration port 1206, then injection throughthe injection lumen causes injectate to be delivered to a site in theblood vessel near the distal exit of the injection lumen. Or, if thevacuum source 1212 is removed from, or simply not coupled to, theaspiration lumen, then injection through the injection lumen may alsocause injectate to be delivered to a site in the blood vessel near thedistal exit of the injection lumen. Either of these techniques may beutilized to apply a medicant to a blood vessel wall, or to anatherosclerotic plaque, or to a thrombus. In some cases, a clot bustingdrug (tissue plasminogen activator-tPA, thrombokinase, urokinase,thrombin, plasmin) is infused into a clot or thrombus, allowing it toact over a period of time. For example, to soften the thrombus overtime. Lytics, glycoprotein inhibitors (GPIs), vasodilators, and otherdrugs may be used to dilate the blood vessel, or treat disease in thearea. The controlled, precision, local delivery allows an efficient useof the drug, with the desired amount delivered to the tissue to betreated with minimal runoff or waste. As many of these drugs are quiteexpensive, this efficiency reduces procedural costs. Because of theprecision diameter of the injection lumen, and its known length, theinjection lumen contains a known volume, or dead space. Thisadditionally allows a known, controlled, precision injection ofmedicant. A representative injection lumen may have a length of 150 cmand have an inner diameter of 0.038 cm (0.015 inches), and thus a totalvolume of only 0.17 ml. The injection lumen volume may be varied, bycontrolling the diameter of the inner diameter of the injection lumenand/or the length of the injection lumen. For example, the injectionlumen volume may be between about 0.08 ml and about 0.26 ml, or betweenabout about 0.14 ml and about 0.20 ml. By injecting through theinjection lumen with a small bore syringe (e.g., 1 ml) or with aprecision pump, an accurate measurement of the medicant delivered can bemade. If, however, the valve 1226, or stopcock, is opened, connectingthe vacuum source 1212 to the aspiration port 1206 and applying a vacuumon the aspiration lumen, a forced aspiration is commenced, as describedherein. As described, the injection lumen may serve as either a closedsystem (aspiration) or an open system (injection of infusate). At thebeginning of a procedure, it is not always known what different actionswill be required, thus the use of the multi-purpose catheter 1202 andmulti-purpose system 1200 may eliminate the need to use multiplecatheters (e.g., both a microcatheter and a single function aspirationcatheter).

FIGS. 20-24 illustrate a multi-purpose system 1240 comprising amulti-purpose catheter 1242 having an infusion/injection port 1244 andan aspiration port 1246. Cooled saline (FIG. 23) may be injected from asaline bag 1248 through a tubing set 1250, attached to the saline bag1248 via a spike 1252. A pump 1254 (FIG. 24), which may include adisplacement pump, such as a piston pump, includes an interface 1256 forattaching a cassette 1258 (FIG. 20). In some embodiments, the pump 1254has moving portions that connect to a moving piston in the cassette 1258to inject controlled amounts of fluid. As described in relation to themulti-purpose system 1200 of FIG. 18, the injection may serve as eithera closed system (aspiration) or an open system (injection of infusate),depending on whether a valve 1260 which couples a vacuum source 1262 tothe aspiration port 1246 via extension tubing 1264 is open or closed, orsimply whether the vacuum source 1262 is attached or not attached. Apressure sensor 1266 communicates with the interior of the extensiontubing 1264, but may communicate with the interior of other parts of theflow path. A cable 1268 carries signals from the pressure sensor 1266 toan aspiration monitoring system 1270, and connects to the aspirationmonitoring system 1270 via an interface 1272, or plug, which isconfigured to connect to a port 1274 of a console 1276 of the aspirationmonitoring system 1270 (FIG. 22). The utility of the multi-purposesystems 1200, 1240 in multiple modes is facilitated by the sterile fluidpath combined with precision volume control (either by small syringe1224, or by the precision pump 1254). In addition, the aspirationmonitoring system 1216, 1270 allows real-time feedback to the user,further facilitating controlled delivery and/or aspiration.

The multipurpose system 1200, 1240 optimizes interventional procedures,such as percutaneous coronary interventions (PCIs), for simplicity, caseflow, and cost. Infusing drugs intracoronary prepares clot foraspiration by placing highly concentrated pharmaco agents directly atthe lesion site, at a location which can be more distal that thataccessible by the tip of a guiding catheter. This can minimize thevolume of drug/medicant/agent used. By limiting the amount of certainmedicants, systemic complications (bleeding, etc.) can be minimized oreliminated. The direct application of the medicant, for example at thethrombus itself, allows it to soften or disaggregate the thrombus. Themaceration of the thrombus, for example by a saline jet 1278 (FIG. 21),keeps the catheter aspiration lumen patent at all times withoutinterruption, and allows standardized catheter advancement technique,for example, moving the catheter slowly from a proximal location to adistal location in the vessel (in relation to the thrombus). Themaceration also dilutes the proximally flowing aspirate for optimalsuction function. In certain situation, aspiration may be performeduntil the normal blood flow is restored (at least to a significantlevel), and then the vacuum source 1262 may be closed off via the valve1260 and cooled injectate may be infused into the blood vessel. Theresultant selective cooling of this area serves to reduce reperfusioninjury by potentially slowing ischemic cell metabolism. The injection ofcooled infusate may be used any time post-aspiration, pre-stenting,without having to remove an aspiration device, advance a new injectiondevice. Because the multi-purpose catheter 1202, 1242 is already inplace, this critical operation may be started immediately. By havingthese functionalities all on one catheter, there is also a cost savingto the user.

In aspiration mode, the aspiration monitoring system 1216, 1270 is ableto monitor proper functioning of the aspiration circuit at all times.The user knows when warnings are communicated or when the system (e.g.,motor) shuts down, that a key event has occurred, which needs attending.This knowledge helps the user avoid plunging the catheter distally,potentially causing distal embolism. In infusion/infusate cooling mode,the pump 1254 moves at a predetermined constant volume or speed todeliver constant temperature cooling infusate. Core temperature feedback(e.g., via rectal, esophageal, ear or other temperature probes) may beused to indicate to the system that further cooling must stop. Forexample, a core body temperature below 35° C. or below 34° C. Thefeedback of a temperature below the threshold may be used to shut downthe pump and/or to send a warning. The infusate path, which is precisionand direct to the catheter tip and/or ischemic area, results inconcentrated cooling, causing the least systemic hypothermic potential.By bypassing the aspiration lumen (e.g., with the valve 1260 closed),unintentional embolic debris is less likely to be infused back into theblood vessel, and less likely to thus be sent downstream to criticalareas. This eliminates the need to exchange devices after flow has beenrestored.

In some cases, in infusion mode, infusate is injected into the fluidinjection lumen with a relatively low pressure. In some cases,maceration is performed at a relatively high pressure. In some cases,the multi-purpose system 1240 may be used without the pump 1254attached, with the saline injections done by hand using a syringeattached to the infusion/injection port 1244. If a clog occurs, thesyringe may be removed and the pump 1254 attached and initiated, forexample, for the purpose of unclogging the fluid injection lumen. In anexemplary procedure, as user places a catheter similar to themulti-purpose catheter 1202 of FIG. 21 in the vasculature. Initially,the user may choose to have neither a pump 1254, nor a syringe 1224attached to the multi-purpose catheter 1202. The user may then commenceaspiration through the aspiration lumen via a vacuum source 1262, thusutilizing the multi-purpose catheter 1202 as a simple (vacuum only)aspiration catheter. If at any time, the user determines that additionalpositive pressure injection of saline and/or medicant is needed, forexample, to overcome clogging, overcome slow aspiration, or to increasemaceration or dilution of the thrombus, the user can attach the pump1254 or the syringe 1224 to the infusion/injection port 1244 and begininjecting the saline and/or medicant.

Using any of the multi-purpose systems 1200, 1240 described herein, adistal pressure may be measured in a diseased coronary artery,peripheral artery, or other artery by the aspiration monitoring system1216, 1270 with aspiration and vacuum turned off or uncoupled, in orderto determine a value for Fractional Flow Reserve (FFR), as disclosed inU.S. Pat. No. 6,565,514, Method and System for Determining PhysiologicalVariables, to Svanerudh et al., which is incorporated herein byreference in its entirety for all purposes. For example, using theembodiment of FIGS. 20-24, in a first step, the user assures that thepump 1254 is not actively pumping saline through the fluid injectionlumen and assures that the vacuum source 1262 is not actively aspiratingthrough the aspiration lumen. In a second step, the user places thedistal end of the aspiration lumen distal to a lesion, stenosis, orpartial blockage of interest in an artery. The user then in a third stepmeasures a pressure at the distal end of the aspiration lumen using theaspiration monitoring system 1270 while also measuring a pressureproximal to the lesion, for example, with a pressure transducer coupledto a guiding catheter. In a fourth step, the user obtains or calculatesthe Fractional Flow Reserve (FFR).

FIGS. 25 through 33 illustrate several different embodiments of deviceshaving a pressure sensor 1300, which is configured to function as acomponent in an aspiration monitoring system sharing some or all of thefunctionality of any one of the aspiration monitoring systems 48, 62,78, 900, 1216, 1270 presented herein. FIG. 25 illustrates an aspirationcatheter 1302 having a distal end 1304 and a proximal end 1306, theproximal end 1306 comprising a female luer connector 1308. The pressuresensor 1300 is in fluid communication with (e.g., fluidly coupled to) alumen of the aspiration catheter 1302. FIG. 26 illustrates a tubing set1310 having a male luer 1312 and a female luer 1314, extension tubing1316, and a stopcock 1318. The pressure sensor 1300 is in fluidcommunication with a lumen of the extension tubing 1316. FIG. 27illustrates a stopcock 1320 having a male luer 1322, a female luer 1324,and a valve 1326, the valve 1326 located proximally of the pressuresensor 1300. The pressure sensor 1300 is in fluid communication with aninternal cavity of the stopcock 1320. FIG. 28 illustrates a stopcock1328 having a male luer 1330, a female luer 1332, and a valve 1334, thevalve 1334 located distally of the pressure sensor 1300. The pressuresensor 1300 is in fluid communication with an internal cavity of thestopcock 1328. FIG. 29 illustrates a syringe 1336 having a male luer1342, a barrel 1338, and a plunger 1340. The syringe 1336 may include alocking feature 1344, which allows the plunger 1340 to be locked inrelation to the barrel 1338, such as a VacLok® syringe.

FIG. 30 illustrates a syringe 1346 having a male luer 1352 (i.e., luerconnector, luer lock), a barrel 1348, a plunger 1350. The syringe 1346may include a locking feature 1344. The pressure sensor 1300 is in fluidcommunication with an internal cavity of the barrel 1348, and may bedirectly connected to either the barrel 1348 or the male luer 1352, or ahollow transitionion 1351 between them. FIG. 31 illustrates anaspiration system 1354 comprising a syringe 1356 having a male luer1357, a barrel 1358 and a plunger 1360. The syringe 1356 may include alocking feature 1344. The aspiration system 1354 also comprises aconnector assembly 1361 comprising a male luer 1362, a valve 1364, and afemale luer 1365 (connected under the male luer 1357 in FIG. 31). Thepressure sensor 1300 is in fluid communication with an internal lumen orcavity between the barrel 1358 of the syringe 1356 and the male luer1362 of the connector assembly 1361. FIG. 32 illustrates an aspirationsystem 1366 comprising a syringe 1368 having a male luer 1369, a barrel1370 and a plunger 1372. The syringe 1368 may include a locking feature1344. The aspiration system 1366 also comprises a connector assembly1373 comprising a male luer 1374, a valve 1376, and a female luer 1377(connected under the male luer 1369 in FIG. 32). The pressure sensor1300 is in fluid communication with an internal lumen or cavity betweenthe barrel 1370 of the syringe 1368 and the male luer 1374 of theconnector assembly 1373. FIG. 33 illustrates an aspiration system 1378comprising a syringe 1380 having a male luer 1382, a barrel 1384 and aplunger 1386. The syringe 1380 may include a locking feature 1344. Theaspiration system 1378 further comprises a tubing set 1388 having a maleluer 1390 and a female luer 1392. A valve 1394 is located eitherproximal or distal to the pressure sensor 1300. Extension tubing 1396may be utilized to connect one or more of the components of the tubingset 1388, but in some cases, the components may be connected directly.The pressure sensor 1300 is in fluid communication with an internallumen of the tubing set 1388. The stopcock or valve in any of theseembodiments may be a one-way stopcock or a three-way stopcock or aone-way valve or a three-way valve. Other embodiments may exist whichcombine one or more elements of each of the embodiments presentedherein. These embodiments are also included within the scope of thisdisclosure. In any of the embodiments in which a male luer is used, itmay be replaced with a female luer or other liquid-tight connector. Inany of the embodiments in which a female luer is used, it may bereplaced with a male luer or other liquid-tight connector. As such,either of the connector assemblies 1361, 1373 may be connected inreverse manner to the syringes 1356, 1368, i.e., wherein the distal endbecomes the proximal end and is thus connected to the syringe 1356,1368, and wherein the proximal end becomes the distal end.

FIG. 34 illustrates a thrombectomy system 300 which incorporates thehigh pressure injection of a liquid, for example sterile salinesolution, in order to macerate and aspirate thrombus 104. A guidingcatheter 108 and a y-connector 148 having a proximal seal 150 and asideport 152 are coupled to a vacuum source 146, as described inrelation to the prior embodiments. A thrombectomy catheter 306 comprisesa distal tube 314 having a distal end 316 and a proximal end 318, theproximal end 318 incorporating one or more sealing members 324 forsealing off an annulus 342 between the guiding catheter 108 and thedistal tube 114, as described in relation to the prior embodiments. Thedistal tube 314 has an aspiration lumen 330. A support/supply tube 368,having a lumen 370, is coupled to the distal tube 314. Thesupport/supply tube 368 serves as a support member for pushing andpulling the thrombectomy catheter 306, but is also a conduit (via thelumen 370) for high pressure saline, which is injected from the proximalend 372 to the distal end 374. The saline is supplied from a salinesource 376 (e.g. saline bag, bottle) and pressurized by a pump 378,through a supply tube 380 and through a luer connector 382 which isconnected to a luer hub 384 coupled to the support/supply tube 368. Insome embodiments, the support/supply tube 368 comprises a hypo tube. Insome embodiments, the support/supply tube 368 comprises stainless steelor nitinol.

FIG. 35 illustrates the proximal end of a guiding catheter 108 used withaspiration catheters, such as the thrombectomy catheter 306 of FIG. 34.A hemostasis valve 389 of y-connector 390 seals over both thesupport/supply tube 391 and the guidewire 28. The hemostasis valve 389(e.g., Touhy-Borst, longitudinally spring-loaded seal, etc.) must beadjusted to allow catheter 306 and/or guidewire 28 movement(translation, rotation), but must keep air from being pulled into thelumens during aspiration. Because of the continual adjustment oftenrequired to the hemostasis valve 389, for example, to aid movement ofthe catheter 306 and/or guidewire 28, the hemostasis valve 389 maycreate significant variability in the amount of air that may leak. Aleak (e.g., at location 393) may be fast, and may be unknown to theuser. A pressure sensor 394 used in conjunction with any of theaspiration monitoring systems described herein allows the user to knowimmediately if the seal of the hemostasis valve 389 of the y-connector390 is not correctly sealed. Additionally, any leaks between the distalluer 388 of the y-connector 390 and the luer hub 386 of the guidingcatheter 108 can be detected by the aspiration monitoring system.Furthermore, any leaks between a luer 392 of the pressure sensor 394 anda sideport 395 of the y-connector 390 or between a luer connector 396 ofthe extension tube 387 and a luer fitting 397 of the pressure sensor 394can be detected by the aspiration monitoring system. The aspirationmonitoring system may be configured to be integral or attachable to anycomponent of the aspiration circuit (e.g., aspiration catheter,syringe/vacuum source), or may be connected in series (at any point)between these components. In some embodiment, the aspiration monitoringsystem may comprise a flow or pressure sensor or detector that is inseries or in parallel with the components, or is configured to be placedin series or in parallel with the components. In any of theseconfigurations, a number of different leak locations may be assessed bythe aspiration monitoring system of the embodiments disclosed herein.The aspiration monitoring system may be configured to detect: changes,relative changes, absolute changes, thresholds, absolute values, thepresence of or the lack of pressure and/or flow. The aspirationmonitoring system may be configured to determine the operation status ofa system including a catheter having an aspiration lumen. In some cases,the aspiration monitoring system may be configured to provideinformation about the operation of the system that is not discernablefrom typical clues such as angiography, sound, feel, or other visual,auditory, tactile or other feedback from the system itself.

Any of the embodiments described herein may include some or all featuresof any of the embodiments described in U.S. Patent Application No.2014/0155931 to Bose et al. (“Bose”) published Jun. 5, 2014, which isincorporated herein by reference in its entirety for all purposes; inaddition, any of the features described herein may be incorporated intoany of the embodiments described in Bose, while remaining within thescope of the present disclosure.

Any of the embodiments described herein may include some or all featuresof any of the embodiments described in U.S. Patent Application No.2010/0204672 to Lockhart et al. (“Lockhart”) published Aug. 12, 2010,which is incorporated herein by reference in its entirety for allpurposes; in addition, any of the features described herein may beincorporated into any of the embodiments described in Lockhart, whileremaining within the scope of the present disclosure.

Embodiments are contemplated for use in peripheral, coronary or cerebralblood vessels, including, but not limited to peripheral, coronary orcerebral arteries. The embodiments may be similar to those described inLockhart.

Stroke is a leading cause of death and disability and a growing problemto global healthcare. Strokes may be caused by a rupture of a cerebralartery (“hemorrhagic stroke”) or a blockage in a cerebral artery due toa thromboembolism (“ischemic stroke”). A thromboembolism is a detachedblood clot that travels through the bloodstream and lodges so as toobstruct or occlude a blood vessel. Between the two types of strokes,ischemic stroke comprises a larger number of cases.

Ischemic stroke treatment may be accomplished via pharmacologicalelimination of the thromboembolism and/or mechanical elimination of thethromboembolism. Pharmacological elimination may be accomplished via theadministration of thombolytics (e.g., streptokinase, urokinase, tissueplasminogen activator (TPA)) and/or anticoagulant drugs (e.g., heparin,warfarin) designed to dissolve and prevent further growth of thethromboembolism. Pharmacologic treatment is non-invasive and generallyeffective in dissolving the thromboembolism. Notwithstanding thesegenerally favorable aspects, significant drawbacks exist with the use ofpharmacologic treatment. One such drawback is the relatively long amountof time required for the thrombolytics and/or anticoagulants to takeeffect and restore blood flow. Given the time-critical nature oftreating ischemic stroke, any added time is potentially devastating.Another significant drawback is the heightened potential of bleeding orhemorrhaging elsewhere in the body due to the thombolytics and/oranticoagulants.

Mechanical elimination of thromboembolic material for the treatment ofischemic stroke has been attempted using a variety of catheter-basedtransluminal interventional techniques. One such interventionaltechnique involves deploying a coil into a thromboembolism (e.g. viacorkscrew action) in an effort to ensnare or envelope thethromboembolism so it can be removed from the patient. Although animprovement over pharmacologic treatments for ischemic stroke, suchcoil-based retrieval systems have only enjoyed modest success(approximately 55%) in overcoming ischemic stroke due to thromboembolicmaterial slipping past or becoming dislodged by the coil. In the lattercase, the dislodgement of thromboembolic material may lead to anadditional stroke in the same artery or a connecting artery.

Another interventional technique involves deploying a basket or netstructure distally (or downstream) from the thromboembolism in an effortto ensnare or envelope the thromboembolism so it can be removed from thepatient. Again, although overcoming the drawbacks of pharmacologictreatment, this nonetheless suffers a significant drawback in that theact of manipulating the basket or net structure distally from theoccluded segment without angiographic roadmap visualization of thevasculature increases the danger of damaging the vessel. In addition,removing the basket or net structure may permit if not causethromboembolic material to enter into connecting arteries. As notedabove, this may lead to an additional stroke in the connecting artery.

A still further interventional technique for treating ischemic strokeinvolves advancing a suction catheter to the thromboembolism with thegoal of removing it via aspiration (i.e. negative pressure). To augmentthe effectiveness of aspiration techniques, a rotating blade has beenemployed to sever or fragment the thromboembolism, which may thereafterbe removed via the suction catheter. While this rotating blade featureimproves the effectiveness of such an aspiration technique, itnonetheless increases the danger of damaging the vessel due to therotating blade.

U.S Publication No. US2006/0058836, System and Method for TreatingIschemic Stroke, to Bose et al., which is incorporated herein byreference in its entirety for all purposes, describes a separator devicethat enhances the effectiveness of the aspiration catheter whileavoiding the risks associated with the prior art rotating blades andsimilar devices. The separator device is deployed from the distal end ofan aspiration catheter positioned in the vessel from which the embolicmaterial is to be removed. The separator may be advanced and retractedout of and into the aspiration catheter multiple times while vacuumpressure is applied to the aspiration catheter. Use of the separatordevice in this manner can facilitate aspiration of the thromboembolicmaterial into the catheter in one of a variety of ways. First, if theseparator is moved into contact with the thromboembolism in the vessel,movement of the separator into contact with the thromboembolism canloosen, separate, or soften pieces of thromboembolic material, such thatpieces of the thromboembolism can be aspirated into the catheter.Second, advancing and retracting the separator serves to remove anyclogs or flow restrictions within the lumen of the aspiration catheterthat might be caused by the passage of thromboembolic material throughthe lumen. Additionally, during retraction of the separator, itsproximal surface may push or plunge loosened material towards and/orinto the distal end of the catheter for subsequent aspiration out of thebody.

It is often desirable to manufacture the separator and aspiration tohave very close tolerances between the outer surface of the separatorand the inner wall of the lumen. Such tolerances help to optimize theeffect of the separator in removing clogs or flow restrictions from thelumen. However, the close tolerances can sometimes cause the separatorto drastically reduce or briefly cut-off aspiration of material towardsand through the lumen as the separator is withdrawn into the lumen.Additional embodiments present herein disclose a thromboembolic removalsystem employing a separator device that improves upon thepreviously-described separator device by allowing aspiration to continueeven when the separator is seated in the lumen.

FIG. 41 illustrates an exemplary embodiment of a thromboembolic removalsystem 610. The thromboembolic removal system 610 includes an optionalguide catheter 612 (or guiding catheter), an aspiration catheter 614, athromboembolic separator 616, and an aspiration pump 618. As will bedescribed in greater detail below, the thromboembolic removal system 610advantageously provides the ability to remove a thromboembolism from acerebral artery within a patient while improving on features of theprior art. Further details can be found in U.S. Publication No. US2006/0058836.

The optional guide catheter 612 includes a tubular catheter member 620having a main lumen 622 extending between a proximal end 624 and adistal end 626. The catheter member 620 may be constructed from anynumber of compositions having suitable biocompatibility and strengthcharacteristics, and may be dimensioned in any number of suitable sizesand lengths depending upon the entry point into the vasculature, thelocation of the thromboembolism, variances in patient anatomy, and anyextenuating circumstances. In an exemplary embodiment, the cathetermember 620 may be constructed from nylon with embedded stainless steelbraid and dimensioned having a length ranging from 70 cm to 120 cm and adiameter ranging from 5 French (0.065 inch) to 9 French (0.117 inch). Aseal 632 on a y-connector 630 is provided for passing the delivery andaspiration catheter 614 through the main lumen 622 of the guide catheter612 in leak-free, hemostatic fashion. As another alternative, thecatheter 614 can be introduced into the vasculature by a sheath.

The aspiration catheter 614 includes a tubular catheter member (element)634 having a main lumen 636 extending between a distal end 638 and aproximal end 640. The catheter element 634 may be constructed from anynumber of compositions having suitable biocompatibility and strengthcharacteristics, and may be dimensioned in any number of suitable sizesand lengths depending upon the entry point into the vasculature, thelocation of the thromboembolism, variances in patient anatomy, and anyextenuating circumstances. In an exemplary embodiment, the cathetermember 634 may be constructed from PEBAX® with embedded stainless steelbraid and dimensioned having a length ranging from 130 cm to 170 cm anda diameter ranging from 2.5 French (0.032 inch) to 5 French (0.065inch).

The aspiration catheter 614 also includes a hub assembly 642 coupled tothe proximal end 640 for the purpose of coupling the lumen 636 to theaspiration pump 618. The hub assembly 642 also includes a seal 644 forallowing the passage of the thromboembolic separator 616 through thelumen 636 in leak-free, hemostatic fashion. The lumen may be coated withPTFE, ETFE, silicone, or another of the various suitable lubriciousmaterials known in the art. A separator element 664 is located near theend of the separator 616.

A first embodiment of a thromboembolic separator 616 is shown in FIGS.42A-42C. The thromboembolic separator 616 of the first embodimentincludes an elongated element 656 having a proximal end (not seen inFIG. 42) and a distal end 657. The elongated element 656 may beconstructed from any number of compositions having suitablebiocompatibility and strength characteristics, and may be dimensioned inany number of suitable sizes and lengths depending upon the entry pointinto the vasculature, the location of the thromboembolism, variances inpatient anatomy, and any extenuating circumstances. In an exemplaryembodiment, the elongated element 656 may be constructed from stainlesssteel and/or Nitinol and dimensioned having a length ranging from 150 cmto 200 cm and a diameter ranging from 0.010 inch to 0.021 inch. Alubricious surface (e.g. a PTFE coating, silicone, hydrophilic coating,or other suitable coatings) may be applied to all or a portion of theelongate element 656 to facilitate movement of the element within thelumen of the delivery/aspiration catheter 614 and/or within thevasculature.

If desired, the elongate element 656 may be coiled along its length asshown in FIGS. 42A and 42B. Alternatively, the portion of the elongateelement proximal to the separator element 664 may be non-coiled with thedistal section 657 portion of the elongate element, distal to theseparator element 664, having a coiled configuration. In either case,the coiled distal section 657 has sufficient flexibility to preventtrauma to vascular tissues during advancement of the separator 616. Thecoil may be positioned around an inner mandrel or core (not shown) of atype commonly found in coiled guidewires.

The distal end of the elongated element 656 includes a generally blunttip element 662 attached or forming part of the distal end thereof. Theblunt nature of the tip element 662 is advantageously atraumatic suchthat it will not cause damage to the interior of the vasculature in theevent it contacts a vessel wall during use.

Separator element 664 is formed of a polymeric material such aspolyurethane or PEBAX® polyether block amides, to name a few. Theseparator element 664 may be a solid, member having a first taperedportion 665 facing in the proximal direction, and a second taperedportion 666 oriented in a distal direction. The tapered portions 665,666 may be contoured in a variety of ways. For example, portion 665 mayhave the conical configuration shown in FIGS. 42A and 42B, or it mightbe substantially planar or slightly convex as used for embodiments shownin U.S Publication No. US2006/0058836, cited above.

The separator element 664 assists in removing any clogs or flowrestrictions that may develop within the lumen of the aspirationcatheter 634 (FIG. 41) due to the passage of thromboembolic materialtherethrough during aspiration. To facilitate this procedure, theseparator element 664 and the catheter 614 are provided with fairlytight tolerances between the diameter of the catheter lumen 636 and thegreatest diameter of the separator element 664. For example, in oneexemplary embodiment, the outer diameter of separator element 664 andthe diameter of lumen 636 may differ by approximately 0.003-0.008inches. The separator element 664 is configured to disrupt thrombus thatmay be the cause of any clogs or flow restrictions within the aspirationcatheter 634. It should be noted that the separator element 664 may be afixed-diameter (non-collapsible) element.

A plurality of longitudinally extending channels or troughs 668 areformed in the separator element. The channels 668 may be oval shapedchannels as shown in FIG. 42B, and include rounded bottom surfaces asshown in the FIG. 42C cross section. The channels are defined by smoothor radiused edges to avoid cutting or damage to vascular tissue in theevent of contact between the vessel lumen and the separator.

The depth D of the channels 668 (FIG. 42C) is in the range of 25 to 80percent of the wall thickness of the separator element 664. In the casewhere the opposed ends of the separator element 664 are tapered, thenthe length L of the channels (FIG. 42B) is in the range of 50 to 80percent of the length of the separator element 664.

In the FIG. 42A-42C embodiment, two such channels 668 are shownpositioned 180° apart. Alternate embodiments may have different numbersof channels, and/or channels arranged with alternate spacings. Forexample, the alternate separator 664 a of FIG. 43 includes threechannels 668 spaced 120° apart

In the illustrated embodiment, the separator element 664 is positionedon the coiled distal section 657 of the elongate element 656. The pitchof a portion of the coiled section 657 may be decreased in certainregions of the coiled distal section 657. Opening the spacing in thecoil in this manner can facilitate adhesion between the polymericmaterial of the separator element and the coil material during themolding process. The spacing between the separator element 664 and thedistal end of the elongate element 656 is preferably long enough toallow the distal-most portion of the elongate element sufficientflexibility to move atraumatically through the vasculature, but shortenough to prevent folding of the distal-most portion during advancementof the elongate element 656. In an exemplary embodiment, the distal endof separator element 664 may be positioned approximately 3-9 mm from thedistal end of the coil. It should be noted that the mandrel or core (notshown) within the coiled section 657 of the elongate element 656 mighthave a tapered diameter selected to enhance the flexibility of thecoiled section.

Referring again to FIG. 41, a handle member 672 may be provided at theproximal end of the separator 616 to provide a purchase point for a userto advance and/or manipulate the separator 616. The handle member 672may be coupled to the elongated element 656 in any suitable fashion,including but not limited to providing a generally rigid extension (notshown) disposed within the elongated element 656 for the purpose ofcoupling the two components together. This coupling may be augmented orstrengthened through the use of any number of adhesives or fusingtechniques.

It will be appreciated that the guide catheter 612, the aspirationcatheter 614, and/or the thromboembolic separator 616 may be providedwith any number of features to facilitate the visualization of theseelements during introduction and usage, including but not limited tohaving the distal regions equipped with radiopaque markers or fillermaterials for improved radiographic imaging. The system 610 mayadditionally be provided with instructions for use setting forth thevarious methods of use described herein, or equivalents thereof.

Methods of using the thromboembolic removal system 610 will now bedescribed with reference to FIGS. 44-47. In a first exemplary method thethromboembolic removal system 610 is introduced into the patient'svasculature, such as via the Seldinger technique. FIG. 44 illustratesthe first step of this process, which involves advancing a guide wire704 to a point proximal to a thromboembolism 700. The guide wire 704 maycomprise any number of commercially available guide wires, the operationof which is well known in the art. However the elongate member 656 ofthe separator 616 may be used instead of the guidewire 704.

FIG. 45 illustrates a second step, which involves advancing the guidecatheter 612 over the guide wire 704 (or the separator member 656) to apoint proximal to the thromboembolism 700. As shown in FIG. 46, theaspiration catheter 614 is then advanced through the guide catheter 612such that the distal end 638 of the aspiration catheter 614 ispositioned at a point proximal to the thromboembolism 700. This ispreferably facilitated by advancing the aspiration catheter 614 over theguide wire 704 (or the separator 616 when used in place of a guidewire). If the separator 616 was not used as the guide wire, the guidewire is next withdrawn and the separator 616 is introduced into theaspiration catheter 614.

At this point, the aspiration pump 618 (FIG. 41) may be activated toestablish negative pressure within the aspiration catheter 614. In thisfashion, negative pressure (pressure gradient) will be created withinthe cerebral artery 702 and exerted upon the thromboembolism 700,causing a reversal of blood flow in the vessel in the region surroundingthe distal end of the aspiration catheter. The separator element 664, ora portion thereof, is advanced slightly from the lumen 636 of theaspiration catheter 614, and is advanced and retracted several timeswithin the distal end of the lumen 636 of the aspiration catheter 614.

Advancing and retracting the separator element 664 (two-headed arrow,FIG. 47) within the lumen 636 of the aspiration catheter 614 serves toremove any clogs or flow restrictions that form within the lumen 636 dueto the passage of thromboembolic material through the lumen 636. Whenthe separator element 664 is positioned within the lumen 636, thechannels 668 in the separator element 664 fluidly couple the lumen 636of the aspiration catheter 614 to the blood vessel. This allowsadvancement and retraction of the separator element 664 into and out ofthe lumen 636 while preventing a nearly complete obstruction of theaspiration catheter 614. The embolic material can thus continue flowingtowards and through the aspiration catheter 614 in a continuous fashion.

In some procedures, the separator element 664 may be advanced intocontact with a portion of the thromboembolism 700, or completely throughthe thromboembolism 700. This will serve to break up or otherwise softenthe thromboembolism 700, or to bias the thromboembolic material towardsthe aspiration catheter 614. Selective advancement of the separatorelement 664 through the thromboembolism 700 and retraction of theseparator element 664 into the aspiration catheter 614, preferably incombination with aspiration, can additionally be used to carry small“bites” of the thromboembolic material into the aspiration catheter 614.For example, the separator element 664 may be passed through thethromboembolic material, displacing some material and thus forming achannel in the material as it moves distally. Once the separator element664 is positioned further into, or distally of, the thromboembolism 700,some of the displaced material may flow back into this channel.Subsequent retraction of the separator element 664 through the material(e.g. through the re-filled channel) will then draw some of the materialinto the aspiration catheter 614. An additional advantage to thechannels is that they reduce the likelihood that any thrombus that hadbeen previously drawn into the lumen will be pushed back out of thedistal end of the lumen when the separator element is pushed out thedistal end of the lumen.

Several advantages are offered when incorporating and using the featuresof any of the aspiration monitoring systems or multi-purpose systemsdescribed herein with the embodiments FIGS. 41-47 and with theembodiments disclosed in U.S Publication No. US2006/0058836 and of U.SPublication No. 2014/0155931. For example, real-time feedback with anyof the aspiration monitoring systems or multi-purpose systems allows theuser to advance the aspiration catheter with confidence, and to quicklyfind clot/thrombus. The user is also notified that it may be anappropriate time to operate the separator element 664. In someembodiments, the user may be notified that it is an appropriate time touse another interventional device, such as a spinning wire device,including, but not limited to the FireBow device (Vesatek, LLC, Irvine,Calif., USA) or the SPINR device (Control Medical Technology/DistalAccess, Salt Lake City, Utah, USA; Merit Medical Systems, South Jordan,Utah, USA). Real-time feedback with any of the aspiration monitoringsystems or multi-purpose systems minimizes blood loss, as the user isable to engage the clot/thrombus quickly, minimizing the time thataspiration is being applied to the aspiration catheter in a pure bloodenvironment (i.e., prior to engaging the clot/thrombus). This is truewhen using aspiration catheters having large aspiration lumen diameters.For example, in aspiration catheters having an aspiration lumen innerdiameter of about 0.152 cm (0.060 inches) or larger, or an aspirationlumen inner diameter of about 0.173 cm (0.068 inches) or larger, or anaspiration lumen inner diameter of about 0.224 cm (0.088 inches) orlarger. In cases in which the clot/thrombus plugs or “corks” theaspiration lumen of the aspiration catheter, for example at the tip ofthe aspiration lumen, the user is quickly notified of this condition, sothat the user may quickly pull back on the aspiration catheter, forexample to remove the entire catheter to unclog it outside the patient,or to replace it. If during pullback of an aspiration catheter with apiece of clot/thrombus clogged in the tip of the aspiration lumen thereis dislodgement of the clot/thrombus, the user is quickly notified ofthe condition (based on the sudden pressure change), and can thus focuson reacting to this situation. For example, imaging or scanning thepatient to determine the resulting location the loose thromboticmaterial, and planning removal of the thrombotic material or confirmingthat the condition is not critical. Additionally, the user may determinewhether to administer drugs or any other adjunctive “rescue” procedure.Additionally, real-time feedback with any of the aspiration monitoringsystems or multi-purpose systems allows the user to determine whetherthere is a connection problem in the system (e.g., connectors which arenot connected or become detached) or a leak in the system (tubing leak,connector leak, leak at junction of parts). If the user is notified thatthere is a connection problem or leak in the system, the user may chooseto close a valve or stopcock to protect or shut off the system. In somecases, the valve may be a hemostasis valve, such as a hemostasis valvewith a variable amount of tightening. In some cases, the hemostasisvalve may not have been tightened completely. In some cases, thestopcock may be a stopcock that can be opened or closed, for example toshut off or protect the system.

FIGS. 36A-36B show an aspiration system 613 which comprises athromboembolic separator 616, an aspiration catheter 614 and anaspiration monitoring system 615. The aspiration catheter 614 includesan aspiration lumen 636 which is configured to couple to a vacuum source673. The vacuum source 673 may comprise a vacuum bottle, vacuum pump, ora syringe, including a lockable syringe, such as a VacLok® syringe. Theaspiration system 613 may incorporate embodiments of any of theaspiration monitoring systems or multi-purpose systems described herein.The aspiration monitoring system 615 of FIGS. 36A-36B includes apressure sensor 394, a measurement device 365, a memory module 367, anda communication device 369. In FIG. 36A, the separator element 664 ofthe thromboembolic separator 616 is extended from the aspiration lumen636 of the aspiration catheter 614, and the communication device 369sends a signal (for example, a green light) indicating that the lumen636 is clear. In FIG. 36B, the separator element 664 is engaged with thedistal end 671 of the aspiration lumen 636, and the communication device369 sends a signal (e.g., an alert signal, for example, a red light)indicating that the lumen 636 is clogged, or rather, blocked. Thus, thecommunication device 369 alerts the user as to the position of theseparator element 664 in relation to the aspiration lumen 636. Thiscommunication to the user, allows the user to perform the procedurequickly and efficiently, saving fluoroscopy time and radiation, andminimizing the amount of contrast media that need be injected. In otherembodiments, a variety of other disrupting elements may be used in paceof the separator element 664, for example, plunging elements, spinningelements, rotating elements, oscillating elements, or any othercomponents that are intended to break up pieces of the thrombus 700 intosmaller pieces.

FIGS. 37A-37B show an aspiration system 1613 comprising an aspirationcatheter 1614 having a short, large bore aspiration lumen 1636 extendingthrough a distal tube 1673. The aspiration catheter 1614 also includes aproximal hub 1691 and an elongate support element 1693, and isconfigured to be placed within the lumen 1622 of a guiding catheter1612, The outer diameter 1675 of the proximal portion 1677 of the distaltube 1673 of the aspiration catheter 1614 is configured to substantiallyseal against the inner diameter 1679 of the guiding catheter 1612,either by capillary resistance, or with an actual seal 1615 (o-ring,etc.) secured to the proximal portion 1677 of the distal tube 1673.Thus, the aspiration lumen 1636 of the aspiration catheter 1614 and thelumen 1622 of the guiding catheter 1612 work together to form a longer,more distally-reachable composite aspiration lumen. Commonly-owned U.S.Pat. No. 9,433,427, Systems and Methods for Management of Thrombosis, toLook et al., which is incorporated herein by reference in its entiretyfor all purposes, describes several embodiments of an aspiration systemfeaturing similar aspiration catheters. As shown in FIG. 37A, aseparator device 1616 is placed by the user through the lumen 1622 ofthe guiding catheter 1612 and the aspiration lumen 1636 of the distaltube 1673, and the separator element 1664 extends distal to theaspiration lumen 1636 of the aspiration catheter 1614. Or, as in FIG.37B, the separator element 1664 may be pulled proximally to occlude thedistal end 1671 of the aspiration lumen 1636 of the aspiration catheter1614. The proximal end 1681 of the separator device 1616 extends out ofthe guiding catheter 1612 and may extend through a hemostasis valve 1632(e.g., of a y-connector 1630). The aspiration monitoring system 615,similar to that of FIGS. 36A-36B, includes a pressure sensor 394, ameasurement device 365, a memory module 367, and a communication device369. The y-connector 1630 is configured to be coupled to a vacuum source673, such that aspiration of thrombus may proceed through the compositelumen which includes the aspiration lumen 1636, the lumen 1622, they-connector 1630, the pressure sensor 394, and any extension tubing1683. The vacuum source 673 may comprise a vacuum bottle, vacuum pump,or a syringe, including a lockable syringe, such as a VacLok® syringe.The vacuum source 673 may be coupled to the pressure sensor 394 or tothe y-connector 1630 by the extension tubing 1683, which may alsoinclude a stopcock 1633, for applying or removing the vacuum/negativepressure. If the hemostasis valve 1632 is not correctly sealed over theseparator device 1616, there may be leakage which confounds theaspiration process. By incorporating the aspiration monitoring systemsor multi-purpose systems described herein with the system of FIGS.37A-37B, the user can be alerted by the communication device 369 asthrombus travels through the aspiration lumen 1636 of the aspirationcatheter 1614 or through the lumen 1622 of the guiding catheter 1612. Ifthe separator element 1664 is pulled into the distal end 1671 of theaspiration lumen 1636 of the aspiration catheter 1614, as shown in FIG.37B, the user is notified by the communication device 369 (alertsignal), and thus can be confident that the retrieved contents (e.g.,thrombus) are well-contained, and the entire system may be safelyremoved from the patient. Also, during aspiration of the thrombus, theuser can be aware of the size of the thrombus being removed, dependingupon whether it, by itself, occludes the lumen, or whether aspirationcontinues.

FIGS. 38-39 illustrate an aspiration system 1400 comprising anaspiration catheter 1402 having an aspiration lumen 1404 having aproximal end 1406 configured to couple to a vacuum source 1408. Thevacuum source 1408 may comprise a syringe, a vacuum bottle, a vacuumpump, or other elements which are configured to apply a vacuum (negativepressure) to the aspiration lumen 1404. In some embodiments, theaspiration catheter 1402 may additionally have a high pressure injectionlumen 1410 for injecting saline from a fluid source 1432, for example,via a high pressure pump 1412. An aspiration monitoring system 1414comprising a pressure transducer 1416 may be coupled to the system, forexample, between the vacuum source 1408 and the aspiration lumen 1404 ofthe aspiration catheter 1402. The aspiration monitoring system 1414 caninclude any of the features described in relation to the otheraspiration monitoring systems 42, 62, 78, 900, 1216, 1270, 615 disclosedherein.

FIG. 39 illustrates the aspiration monitoring system 1414 with anelongate member 1418, such as a guidewire, inserted through theaspiration lumen 1404. A proximal portion 1420 extends from the proximalend 1406 of the aspiration lumen 1404, and may be rotatable within adynamic seal 1422, which may be included within a y-connector 1424(e.g., hemostasis valve). A rotating device 1426 (wire spinning device)has a handle 1428 which may be grasped by the hand 1430 of a user 1433,and a connector 1434 which is configured to rotationally couple to theproximal portion 1420 of the elongate member 1418.

The rotating device 1426 of wire spinning device includes a drive memberthat allows it to rotate the elongate member 1418 either by motorized orhand-driven operation. Exemplary rotating devices 1426 are described inU.S. Pat. No. 9,119,942 to Rollins et al. (“Rollins I”) issued Sep. 1,2015, or in U.S. Pat. No. 9,119,941 to Rollins et al. (“Rollins II”)issued Sep. 1, 2015, both of which are incorporated by reference intheir entireties for all purposes. The rotating device 1426 or wirespinning device described in FIGS. 38 and 39 may be replaced by severaldifferent spinning devices, such as the FireBow device (Vesatek, LLC,Irvine, Calif., USA); the SPINR device (Control MedicalTechnology/Distal Access, Salt Lake City, Utah, USA; Merit MedicalSystems, South Jordan, Utah, USA); or the drive system configured to usewith the ROTAREX®S device (Straub Medical, Wangs, Switzerland).

By causing the elongate member 1418 to spin within the aspiration lumen1404, thrombus may be macerated within the aspiration lumen 1404 inorder to facilitate the aspiration of the blood or thrombus through theaspiration lumen 1404. The distal end of the elongate member 1418 mayextend from the distal end of the aspiration lumen 1404 or may belocated within the aspiration lumen 1404. In cases wherein the distalend of the elongate member 1418 extends from the aspiration lumen 1404,the elongate member 1418 may also be used to macerate thrombus outsideof the aspiration lumen (e.g., within a blood vessel). FIGS. 40A-40Dillustrate different configurations of the elongate member 1418 whichmay aid in macerating or breaking up thrombus or clot. The elongatemember 1418A of FIG. 40A is straight or substantially straight (nosignificant bends) and when it is rotated in a rotational direction R1by the rotating device 1426, it may macerate the thrombus by creating aspinning and mixing motion within the aspiration lumen 1404. Theelongate member 1418B of FIG. 40B is has an undulating or wavy shapethat is mostly or completely contained along a plane P1 and when it isrotated in a rotational direction R1 by the rotating device 1426, it maymacerate the thrombus by creating a beating or whipping pattern. Thoughthe rotational direction is depicted as counter-clockwise in FIGS. 40Aand 40B, a clockwise direction may also be used, or a combination ofboth clockwise and counter-clockwise rotation. The elongate member 1418Cof FIG. 40C is a spiral or helical shape and when it is rotated in arotational direction R2 by the rotating device 1426, it may macerate ordisrupt the thrombus within the aspiration lumen 1404 and/or may createa vortex or even an Archimedes screw effect within the aspiration lumen1404. The elongate member 1418D of FIG. 40D is has a wavy or undulatingpattern or helical or spiral pattern that is off center and may berotated in a rotational direction R2 by the rotating device 1426 tocreate the effect described in relation to the elongate members 1418Band 1418C, while the main shaft 1436 continually wipes the interiorwalls of the aspiration lumen 1404 to promote flow throughout theaspiration lumen 1404. Though the rotational direction is depicted asclockwise in FIGS. 40C and 40D, a counter-clockwise direction may alsobe used, or a combination of both clockwise and counter-clockwiserotation. The direction of winding of the helical or spiral patterns ofthe elongate members 1418C, 1418D may be either left-hand or right-hand,and in some embodiments, may even be a combination of the two.

While the foregoing is directed to embodiments of the presentdisclosure, other and further embodiments may be devised withoutdeparting from the basic scope thereof.

What is claimed is:
 1. A system for removal of blood or thrombuscomprising: a vacuum source; an aspiration catheter having an elongateshaft including an aspiration lumen having a proximal end and a distalend, the proximal end configured to couple to the vacuum source, thedistal end having an orifice; an elongate member configured forplacement through the aspiration lumen, the elongate member having aproximal portion configured to extend from the proximal end of theaspiration lumen; a rotating device configured to couple to the proximalportion of the elongate member, the rotating device comprising a bodyand a rotation element, the body configured to be gripped by a user andthe rotational element configured to rotate the elongate member when therotating device is coupled to the elongate member; and a self-containedmonitoring device for real time monitoring of catheter aspiration,configured for removable connection in between the aspiration catheterand the vacuum source, comprising: a housing having a first port adaptedfor detachable connection to the vacuum source and a second port adaptedfor detachable connection with the aspiration catheter; a pressuresensor in fluid communication with an interior of the housing; ameasurement device coupled to the pressure sensor and configured formeasuring deviations in fluid pressure; and a communication devicecoupled to the measurement device and configured to generate an alertsignal when a deviation in fluid pressure measured by the measurementdevice exceeds a pre-set threshold.
 2. The system of claim 1, whereinthe elongate member is configured to macerate thrombus such that it canbe aspirated through the aspiration lumen.
 3. The system of claim 1,wherein the elongate member is straight or substantially straight. 4.The system of claim 1, wherein the elongate member has a wavy orundulating form.
 5. The system of claim 1, wherein the elongate memberhas a helical or spiral form.
 6. The system of claim 5, wherein theelongate member comprises a coil having a central axis.
 7. The system ofclaim 6, wherein the elongate member comprises a substantially straightshaft having a longitudinal axis and a distal end coupled to a proximalend of the coil, and wherein the central axis of the coil and thelongitudinal axis of the substantially straight shaft are not co-linear.8. The system of claim 7, wherein the coil has an outer diameter, andwherein the longitudinal axis of the substantially straight shaftextends along a line closer to a circular projection of the outerdiameter of the coil than the central axis of the coil.
 9. The system ofclaim 8, wherein the longitudinal axis of the substantially straightshaft extends along a line within the circular projection of the outerdiameter of the coil.
 10. The system of claim 1, wherein thecommunication device is configured to generate a first type of alert inresponse to a deviation measured by the measurement device comprisingone or more increases and decreases of vacuum pressure.
 11. The systemof claim 10, wherein the first type of alert comprises at least one ofan audible alert, a visible alert, and a tactile alert.
 12. The systemof claim 10, wherein the communication device is configured to generatea second type of alert in response to the deviation comprising one ormore increases and decreases of vacuum pressure no longer being measuredby the measurement device.
 13. The system of claim 1, further comprisinga memory module, wherein the measurement device is configured to comparemeasured deviations in pressure with information contained in the memorymodule.
 14. The system of claim 1, wherein the measurement devicecomprises a microprocessor.
 15. The system of claim 1, wherein the alertsignal is configured to indicate a clogged condition.
 16. The system ofclaim 1, wherein the alert signal is configured to indicate a systemleak.
 17. The system of claim 1, wherein the alert signal is configuredto indicate thrombus being aspirated.
 18. The system of claim 1, whereinthe alert signal is configured to indicate thrombus no longer beingaspirated.
 19. The system of claim 1, wherein the alert signal isconfigured to indicate at least two of the states selected from thegroup consisting of a clogged condition, a system leak, thrombus beingaspirated, and thrombus no longer being aspirated.
 20. The system ofclaim 1, wherein the elongate member is configured to guide a catheterthrough a portion of the vascular system of a subject.
 21. The system ofclaim 20, where the elongate member is configured to guide theaspiration catheter through the portion of the vascular system of thesubject.
 22. The system of claim 1, wherein the elongate member is aguidewire.